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  • 1. Aartsen, M. G.
    et al.
    Botner, Olga
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Burgman, Alexander
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Hallgren, Allan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Pérez de los Heros, Carlos
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Unger, Isaak
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Zoecklein, M.
    Efficient propagation of systematic uncertainties from calibration to analysis with the SnowStorm method in IceCube2019In: Journal of Cosmology and Astroparticle Physics, E-ISSN 1475-7516, no 10, article id 048Article in journal (Refereed)
    Abstract [en]

    Efficient treatment of systematic uncertainties that depend on a large number of nuisance parameters is a persistent difficulty in particle physics and astrophysics experiments. Where low-level effects are not amenable to simple parameterization or re-weighting, analyses often rely on discrete simulation sets to quantify the effects of nuisance parameters on key analysis observables. Such methods may become computationally untenable for analyses requiring high statistics Monte Carlo with a large number of nuisance degrees of freedom, especially in cases where these degrees of freedom parameterize the shape of a continuous distribution. In this paper we present a method for treating systematic uncertainties in a computationally efficient and comprehensive manner using a single simulation set with multiple and continuously varied nuisance parameters. This method is demonstrated for the case of the depth-dependent effective dust distribution within the IceCube Neutrino Telescope.

  • 2.
    Abdel-Hafiez, Mahmoud
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China;Harvard Univ, Lyman Lab Phys, Cambridge, MA 02138 USA;Natl Univ Sci & Technol MISiS, Moscow 119049, Russia.
    Thiyagarajan, R.
    Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China.
    Majumdar, Arnab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Luo, Wei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Vasiliev, A. N.
    Natl Univ Sci & Technol MISiS, Moscow 119049, Russia;Natl Res South Ural State Univ, Chelyabinsk 454080, Russia;Moscow MV Lomonosov State Univ, Moscow 119991, Russia.
    Maarouf, A. A.
    Imam Abdulrahman Bin Faisal Univ, Inst Res & Med Consultat, Dept Phys, Dammam 31441, Saudi Arabia.
    Zybtsev, S. G.
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    Pokrovskii, V. Ya
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    V-Zaitsev-Zotov, S.
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    Pavlovskiy, V. V.
    RAS, Inst Radioengn & Elect, Moscow 125009, Russia.
    Pai, Woei Wu
    Natl Taiwan Univ, Ctr Condensed Matter Sci, Taipei 106, Taiwan;Natl Taiwan Univ, Dept Phys, Taipei 10610, Taiwan.
    Yang, W.
    Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China.
    Kulik, L. , V
    Pressure-induced reentrant transition in NbS3 phases: Combined Raman scattering and x-ray diffraction study2019In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 99, no 23, article id 235126Article in journal (Refereed)
    Abstract [en]

    We report the evolution of charge density wave states under pressure for two NbS3 phases: triclinic (phase I) and monoclinic (phase II) at room temperature. Raman and x-ray diffraction (XRD) techniques are applied. The x-ray studies on the monoclinic phase under pressure show a compression of the lattice at different rates below and above similar to 7 GPa but without a change in space group symmetry. The Raman spectra of the two phases evolve similarly with pressure; all peaks almost disappear in the similar to 6-8 GPa range, indicating a transition from an insulating to a metallic state, and peaks at new positions appear above 8 GPa. The results suggest suppression of the ambient charge-density waves and their subsequent recovery with new orderings above 8 GPa.

  • 3. Abdi-Jalebi, Mojtaba
    et al.
    Andaji-Garmaroudi, Zahra
    Cacovich, Stefania
    Stavrakas, Camille
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Richter, Johannes M.
    Alsari, Mejd
    Booker, Edward P.
    Hutter, Eline M.
    Pearson, Andrew J.
    Lilliu, Samuele
    Savenije, Tom J.
    Rensmo, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Divitini, Giorgio
    Ducati, Caterina
    Friend, Richard H.
    Stranks, Samuel D.
    Maximizing and stabilizing luminescence from halide perovskites with potassium passivation2018In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 555, p. 497-501Article in journal (Refereed)
    Abstract [en]

    Metal halide perovskites are of great interest for various high-performance optoelectronic applications. The ability to tune the perovskite bandgap continuously by modifying the chemical composition opens up applications for perovskites as coloured emitters, in building-integrated photovoltaics, and as components of tandem photovoltaics to increase the power conversion efficiency. Nevertheless, performance is limited by non-radiative losses, with luminescence yields in state-of-the-art perovskite solar cells still far from 100 per cent under standard solar illumination conditions. Furthermore, in mixed halide perovskite systems designed for continuous bandgap tunability2 (bandgaps of approximately 1.7 to 1.9 electronvolts), photoinduced ion segregation leads to bandgap instabilities. Here we demonstrate substantial mitigation of both non-radiative losses and photoinduced ion migration in perovskite films and interfaces by decorating the surfaces and grain boundaries with passivating potassium halide layers. We demonstrate external photoluminescence quantum yields of 66 per cent, which translate to internal yields that exceed 95 per cent. The high luminescence yields are achieved while maintaining high mobilities of more than 40 square centimetres per volt per second, providing the elusive combination of both high luminescence and excellent charge transport. When interfaced with electrodes in a solar cell device stack, the external luminescence yield—a quantity that must be maximized to obtain high efficiency—remains as high as 15 per cent, indicating very clean interfaces. We also demonstrate the inhibition of transient photoinduced ion-migration processes across a wide range of mixed halide perovskite bandgaps in materials that exhibit bandgap instabilities when unpassivated. We validate these results in fully operating solar cells. Our work represents an important advance in the construction of tunable metal halide perovskite films and interfaces that can approach the efficiency limits in tandem solar cells, coloured-light-emitting diodes and other optoelectronic applications.

  • 4.
    Abdi-Jalebi, Mojtaba
    et al.
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Pazoki, Meysam
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Dar, M. Ibrahim
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, Lausanne, Switzerland.
    Alsari, Mejd
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Sadhanala, Aditya
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Diyitini, Giorgio
    Univ Cambridge, Dept Mat Sci & Met, Charles Babbage Rd, Cambridge, England.
    Imani, Roghayeh
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lilliu, Samuele
    Univ Sheffield, Dept Phys & Astron, Sheffield, S Yorkshire, England; UAE Ctr Crystallog, Dubai, U Arab Emirates.
    Kullgren, Jolla
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Rensmo, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Gratzel, Michael
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, Lausanne, Switzerland.
    Friend, Richard H.
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Dedoping of Lead Halide Perovskites Incorporating Monovalent Cations2018In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 7, p. 7301-7311Article in journal (Refereed)
    Abstract [en]

    We report significant improvements in the optoelectronic properties of lead halide perovskites with the addition of monovalent ions with ionic radii close to Pb2+. We investigate the chemical distribution and electronic structure of solution processed CH3NH3PbI3 perovskite structures containing Na+, Cu+, and Ag+, which are lower valence metal ions than Pb2+ but have similar ionic radii. Synchrotron X-ray diffraction reveals a pronounced shift in the main perovskite peaks for the monovalent cation-based films, suggesting incorporation of these cations into the perovskite lattice as well as a preferential crystal growth in Ag+ containing perovskite structures. Furthermore, the synchrotron X-ray photoelectron measurements show a significant change in the valence band position for Cu- and Ag-doped films, although the perovskite bandgap remains the same, indicating a shift in the Fermi level position toward the middle of the bandgap. Such a shift infers that incorporation of these monovalent cations dedope the n-type perovskite films when formed without added cations. This dedoping effect leads to cleaner bandgaps as reflected by the lower energetic disorder in the monovalent cation-doped perovskite thin films as compared to pristine films. We also find that in contrast to Ag+ and Cu+, Na+ locates mainly at the grain boundaries and surfaces. Our theoretical calculations confirm the observed shifts in X-ray diffraction peaks and Fermi level as well as absence of intrabandgap states upon energetically favorable doping of perovskite lattice by the monovalent cations. We also model a significant change in the local structure, chemical bonding of metal-halide, and the electronic structure in the doped perovskites. In summary, our work highlights the local chemistry and influence of monovalent cation dopants on crystallization and the electronic structure in the doped perovskite thin films.

  • 5.
    Abid, Abdul Rahman
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    X-ray Absorption and Fragmentationas Initial Steps of Radiation Damage in Free Organic Molecules and Nanoparticles2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Understanding the molecular radiation damage is crucial in radiobiology, molecular physics, and atmospheric science. In this thesis, the initial steps of radiation damage of anhydrous gas-phase molecules and hydrated nanoparticles were studied using synchrotron radiation based electron-ion coincidence spectroscopy and X-ray absorption spectroscopy under vacuum conditions. Electron - ion coincidence spectroscopy was used to study the photofragmentation and molecular dynamics of the isolated gas-phase molecules. In addition to the photofragmentation of the gas-phase molecules, the effect of the initial ionization site, initial molecular geometry, and the intramolecular chemical environment has been studied. In avobenzone, core ionization leads to massive fragmentation, with a slight site-selectivity concerning fragment production. In ortho-aminobenzoic acid, core ionization leads to the production of a hydronium ion, indicating that the importance of functional group's position for double intramolecular hydrogen transfer. X-ray absorption spectroscopy was used to probe hydrated nanoparticles prepared at different relative humidities. In hydrated inorganic and mixed inorganic-organic nanoparticles, water is present in a liquid-like state. With different ranges of relative humidity, the primary hydration layers of the hydrated nanoparticles stays the same. In mixed nanoparticles, there is evidence for interaction between the included organic biomolecule with the inorganic and/or water molecules.   

    List of papers
    1. The effect of relative humidity on CaCl2 nanoparticles studied by soft X-ray absorption spectroscopy
    Open this publication in new window or tab >>The effect of relative humidity on CaCl2 nanoparticles studied by soft X-ray absorption spectroscopy
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    2021 (English)In: RSC Advances, E-ISSN 2046-2069, Vol. 11, no 4, p. 2103-2111Article in journal (Refereed) Published
    Abstract [en]

    Ca- and Cl-containing nanoparticles are common in atmosphere, originating for example from desert dust and sea water. The properties and effects on atmospheric processes of these aerosol particles depend onthe relative humidity (RH) as they are often both hygroscopic and deliquescent. We present here a study of surface structure of free-flying CaCl2 nanoparticles (CaCl2-NPs) in the 100 nm size regime prepared at different humidity levels (RH: 11–85%). We also created mixed nanoparticles by aerosolizing a solution ofCaCl2 and phenylalanine (Phe), which is a hydrophobic amino acid present in atmosphere. Information of hydration state of CaCl2-NPs and production of mixed CaCl2 + Phe nanoparticles was obtained using soft X-ray absorption spectroscopy (XAS) at Ca 2p, Cl 2p, C 1s, and O 1s edges. We also report Ca 2p andCl 2p X-ray absorption spectra of an aqueous CaCl2 solution. The O 1s X-ray absorption spectra measured from hydrated CaCl2-NPs resemble liquid-like water spectrum, which is heavily influenced by the presence of ions. Core level spectra of Ca2+ and Cl- ions do not show a clear dependence of % RH, indicating that the first coordination shell remains similar in all measured hydrated CaCl2-NPs, but they differ from aqueous solution and solid CaCl2.

    Place, publisher, year, edition, pages
    Royal Society of Chemistry, 2021
    National Category
    Atom and Molecular Physics and Optics
    Research subject
    Physics
    Identifiers
    urn:nbn:se:uu:diva-435531 (URN)10.1039/d0ra08943e (DOI)000609773700022 ()
    Funder
    EU, Horizon 2020, 713606Academy of FinlandSwedish Research Council, VR 2017-04162
    Available from: 2021-02-25 Created: 2021-02-25 Last updated: 2024-01-15Bibliographically approved
    2. Electron-ion coincidence spectroscopy of a large organic molecule: photofragmentation of avobenzone after valence and core ionisation
    Open this publication in new window or tab >>Electron-ion coincidence spectroscopy of a large organic molecule: photofragmentation of avobenzone after valence and core ionisation
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    2020 (English)In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 53, no 24, article id 244001Article in journal (Refereed) Published
    Abstract [en]

    The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

    Place, publisher, year, edition, pages
    IOP PUBLISHING LTD, 2020
    Keywords
    PEPIPICO, photofragmentation, time-of-flight mass spectrometry, radiation damage, electron spectroscopy, avobenzone
    National Category
    Atom and Molecular Physics and Optics
    Identifiers
    urn:nbn:se:uu:diva-428313 (URN)10.1088/1361-6455/abc228 (DOI)000590714400001 ()
    Funder
    EU, Horizon 2020, 730872Swedish Research Council, VR 2017-04162Swedish Research Council, 2018-07152Vinnova, 2018-04969Swedish Research Council Formas, 2019-02496
    Available from: 2020-12-14 Created: 2020-12-14 Last updated: 2021-02-25Bibliographically approved
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  • 6.
    Abid, Abdul Rahman
    et al.
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland.;Uppsala Univ, Mol & Condensed Matter Phys, Uppsala, Sweden..
    Pelimanni, Eetu
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Reinhardt, Maximilian
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Boudjemia, Nacer
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Kivimaki, Antti
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland.;Lund Univ, Max Lab 4, Lund, Sweden..
    Huttula, Marko
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Björneholm, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Patanen, Minna
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Electron-ion coincidence spectroscopy of a large organic molecule: photofragmentation of avobenzone after valence and core ionisation2020In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 53, no 24, article id 244001Article in journal (Refereed)
    Abstract [en]

    The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

  • 7.
    Abid, Abdul Rahman
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Pelimanni, Eetu
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Reinhardt, Maximilian
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Boudjemia, Nacer
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Kivimaki, Antti
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland.;Lund Univ, Max Lab 4, Lund, Sweden..
    Huttula, Marko
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Björneholm, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Patanen, Minna
    Univ Oulu, Nano & Mol Syst Res Unit, Oulu, Finland..
    Electron-ion coincidence spectroscopy of a large organic molecule: photofragmentation of avobenzone after valence and core ionisation2020In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 53, no 24, article id 244001Article in journal (Refereed)
    Abstract [en]

    The Avobenzone (AVOB) molecule is very photoactive and undergoes irreversible degradation upon irradiation. We studied its valence and core-level (C1s and O1s) photoionisation and subsequent photofragmentation with photoelectron spectroscopy and photoelectron-photoion-photoion coincidence (PEPIPICO) spectroscopy. AVOB is one of the largest molecules studied with this technique. The results show that the AVOB molecule dissociates into an extensive range of fragments by different pathways with little element or site-selectivity. The coincident maps were used to determine selected fragment separation sequences by analysing the slopes of patterns from ion pairs after the core ionisation. Charge delocalisation over the benzene rings and their relative stability favor fragmentation by cleavage of the bridge between them.

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    fulltext
  • 8. Abu-samha, M
    et al.
    Borve, K. J.
    Winkler, M
    Harnes, J
    Saethre, L. J.
    Lindblad, A
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    Bergersen, H
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    Björneholm, O
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Svensson, S
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    Öhrwall, G
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    The local structure of small water clusters: imprints on the core-level photoelectron spectrum2009In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 42, no 5, p. 055201-Article in journal (Refereed)
    Abstract [en]

    We report on an O 1s photoelectron-spectroscopy study of small neutral water clusters produced by adiabatic expansion. The photoelectron spectra were acquired under two different experimental conditions. At intermediate resolution, the cluster signal was characterized by a very broad O 1s peak with a flat top. In the second set of measurements, resolution was significantly increased at the cost of lower count rates. The cluster signal was now partly resolved into a bimodal structure. Extensive theoretical calculations were undertaken to facilitate an interpretation of the spectrum. These results suggest that the bimodal feature may be ascribed to ionization of water molecules in different hydrogen-bonding configurations, more specifically, molecules characterized by donation of either one or both hydrogen atoms in H-bonding.

  • 9.
    Agelii, Harald
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Dipole Orientation of Gas Phase Ubiquitin Using Time Dependent Electric Fields2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The method of dipole orientation of protein complexes using electric fields plays a key role in the development of single particle imaging, since it enables orientation of the protein in vacuum. In the orientation process the protein is exposed to an external electric field along which the dipole axis of the protein will eventually align. Earlier studies using molecular dynamics simulations have implemented a constant electric field to examine the dipole orientation process. However, when injected into the electric field the protein experiences a gradually increasing field strength converging to some terminal field strength rather than a constant electric field. In order to examine the effects of the time-dependant nature of the electric field, in comparison to a constant one, fields with different time dependances were implemented in molecular dynamics simulations in vacuum performed with GROMACS. Ubiquitin was chosen as a model protein. The results of the study show time-increasing fields tend to result in slower orientation, but preserve the structure of the protein better than for a constant field. It was also shown that after 10 ns electric field exposure, with terminal field strengths greater  or equal to 0.6Vnm^-1, there was no apparent difference of the average degree of orientation of proteins within the time-increasing fields and the constant one. However, for fields of greater or equal to 1.5Vnm^-1 the constant field tended to result in a larger change of the protein structure.

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    Dipole Orientation of Gas Phase Ubiquitin Using Time Dependent Electric Fields
  • 10.
    Agåker, Marcus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Andersson, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Englund, J.C.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Rausch, Joachim
    Giessen University.
    Rubensson, Jan-Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Nordgren, Joseph
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Spectroscopy in the vacuum-ultraviolet2011In: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 5, p. 248-Article in journal (Refereed)
  • 11.
    Agåker, Marcus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden.
    Mueller, Frieder
    FMB Feinwerk & Messtech GmbH, Friedrich Woehler Str 2, D-12489 Berlin, Germany.
    Jensen, Brian Norsk
    Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden.
    Åhnberg, Karl
    Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden.
    Sjöblom, Peter
    Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden.
    Deiwiks, Jochen
    FMB Feinwerk & Messtech GmbH, Friedrich Woehler Str 2, D-12489 Berlin, Germany.
    Henniger, Hans
    FMB Feinwerk & Messtech GmbH, Friedrich Woehler Str 2, D-12489 Berlin, Germany.
    Pärna, Rainer
    Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden;Univ Tartu, Inst Phys, W Oswaldi 1, EE-51014 Tartu, Estonia.
    Knudsen, Jan
    Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden.
    Thiagarajan, Balasubramanian
    Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden.
    Såthe, Conny
    Lund Univ, MAX Lab 4, SE-22100 Lund, Sweden.
    A five-axis parallel kinematic mirror unit for soft X-ray beamlines at MAX IV2020In: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 27, p. 262-271Article in journal (Refereed)
    Abstract [en]

    With the introduction of the multi-bend achromats in the new fourth-generation storage rings the emittance has decreased by an order of magnitude resulting in increased brightness. However, the higher brightness comes with smaller beam sizes and narrower radiation cones. As a consequence, the requirements on mechanical stability regarding the beamline components increases. Here an innovative five-axis parallel kinematic mirror unit for use with soft X-ray beamlines using off-axis grazing-incidence optics is presented. Using simulations and measurements from the HIPPIE beamline at the MAX IV Laboratory it is shown that it has no Eigen frequencies below 90 Hz. Its positioning accuracy is better than 25 nm linearly and 17-35 mu rad angularly depending on the mirror chamber dimensions.

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    FULLTEXT01
  • 12. Ahmad, Y.
    et al.
    Dubois, M.
    Guerin, K.
    Hamwi, A.
    Fawal, Z.
    Kharitonov, A. P.
    Generalov, A. V.
    Klyushin, A. Yu.
    Simonov, K. A.
    V.A. Fock Institute of Physics, St. Petersburg State University, St. Petersburg 198504, Russia.
    Vinogradov, Nikolay A.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics. V.A. Fock Institute of Physics, St. Petersburg State University, St. Petersburg 198504, Russia.
    Zhdanov, I. A.
    V.A. Fock Institute of Physics, St. Petersburg State University, St. Petersburg 198504, Russia.
    Preobrajenski, A. B.
    MAX-lab, Lund University, Box 118, 22100 Lund, Sweden.
    Vinogradov, A. S.
    V.A. Fock Institute of Physics, St. Petersburg State University, St. Petersburg 198504, Russia.
    NMR and NEXAFS Study of Various Graphite Fluorides2013In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 117, no 26, p. 13564-13572Article in journal (Refereed)
    Abstract [en]

    Graphite fluorides with different structural types (CyF)(n) (y = 2.5, 2, and 1) and room temperature graphite fluorides were studied by solid state,NMR and NEXAFS. Data extracted from those two techniques are complementary, providing information about the C-F bonding and the hybridization character of the carbon atom valence states. The comparison of data obtained by different methods such as NMR, Raman, and X-ray absorption leads to similar conclusions regarding the chemical bonding in fluorographites. Several major configurations of fluorinated graphites are discussed, that is, planar sheets with mainly sp(2) hybridization in room temperature graphite fluorides and corrugated sheets with sp(3) hybridization in covalent high temperature graphite fluoride. Different references such as highly oriented pyrolytic graphite (HOPG), graphitized carbon nanodiscs (graph-CNDs) and nanodiamonds (NDs) have also been investigated for comparison.

  • 13. Ahmadi, Sareh
    et al.
    Agnarsson, Bjorn
    Bidermane, Ieva
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Wojek, Bastian M.
    Noel, Quentin
    Sun, Chenghua
    Gothelid, Mats
    Site-dependent charge transfer at the Pt(111)-ZnPc interface and the effect of iodine2014In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 140, no 17, p. 174702-Article in journal (Refereed)
    Abstract [en]

    The electronic structure of ZnPc, from sub-monolayers to thick films, on bare and iodated Pt(111) is studied by means of X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and scanning tunneling microscopy. Our results suggest that at low coverage ZnPc lies almost parallel to the Pt(111) substrate, in a non-planar configuration induced by Zn-Pt attraction, leading to an inhomogeneous charge distribution within the molecule and an inhomogeneous charge transfer to the molecule. ZnPc does not form a complete monolayer on the Pt surface, due to a surface-mediated intermolecular repulsion. At higher coverage ZnPc adopts a tilted geometry, due to a reduced molecule-substrate interaction. Our photoemission results illustrate that ZnPc is practically decoupled from Pt, already from the second layer. Pre-deposition of iodine on Pt hinders the Zn-Pt attraction, leading to a non-distorted first layer ZnPc in contact with Pt(111)-I(root 3x root 3) or Pt(111)-I(root 7x root 7), and a more homogeneous charge distribution and charge transfer at the interface. On increased ZnPc thickness iodine is dissolved in the organic film where it acts as an electron acceptor dopant. (C) 2014 AIP Publishing LLC.

  • 14.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Massel, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Ahmadi, Majid
    Delft University of Technology, Kavli Institute of Nanoscience, Faculty of Applied Sciences.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Zipprich, Wolfgang
    Volkswagen AG.
    Marzano, Fernanda
    Scania CV AB.
    Duda, Laurent
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    How Mn/Ni ordering controls electrochemical performance in high-voltage spinel LiNi0.44Mn1.56O4 (LNMO) with fixed oxygen contentManuscript (preprint) (Other academic)
  • 15.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Massel, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Ahmadi, Majid
    Delft Univ Technol, Fac Appl Sci, Kavli Inst Nanosci, NL-2628 CJ Delft, Netherlands..
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Zipprich, Wolfgang
    Volkswagen AG, D-38436 Wolfsburg, Germany..
    Marzano, Fernanda
    Scania CV AB, SE-15187 Sodertalje, Sweden..
    Duda, Laurent
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    How Mn/Ni Ordering Controls Electrochemical Performance in High-Voltage Spinel LiNi0.44Mn1.56O4 with Fixed Oxygen Content2020In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 3, no 6, p. 6001-6013Article in journal (Refereed)
    Abstract [en]

    The crystal structure of LiNi0.5O4 (LNMO) can adopt either low-symmetry ordered (Fd (3) over barm) or high-symmetry disordered (P4(3)32) space group depending on the synthesis conditions. A majority of published studies agree on superior electrochemical performance of disordered LNMO, but the underlying reasons for improvement remain unclear due to the fact that different thermal history of the samples affects other material properties such as oxygen content and particle morphology. In this study, ordered and disordered samples were prepared with a new strategy that renders samples with identical properties apart from their cation ordering degree. This was achieved by heat treatment of powders under pure oxygen atmosphere at high temperature with a final annealing step at 710 degrees C for both samples, followed by slow or fast cooling. Electrochemical testing showed that cation disordering improves the stability of material in charged (delithiated) state and mitigates the impedance rise in LNMO parallel to LTO (Li4Ti5O12) and LNMO parallel to Li cells. Through X-ray photoelectron spectroscopy (XPS), thicker surface films were observed on the ordered material, indicating more electrolyte side reactions. The ordered samples also showed significant changes in the Ni 2p XPS spectra, while the generation of ligand (oxygen) holes was observed in the Ni-O environment for both samples using X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). Moreover, high-resolution transmission electron microscopy (HRTEM) images indicated that the ordered samples show a decrease in ordering near the particle surface after cycling and a tendency toward rock-salt-like phase transformations. These results show that the structural arrangement of Mn/Ni (alone) has an effect on the surface and "nearsurface" properties of LNMO, particularly in delithiated state, which is likely connected to the bulk electronic properties of this electrode material.

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  • 16. Alagia, M
    et al.
    Coreno, M
    Farrokhpour, H
    Franceschi, P
    Mihelic, A
    Moise, A
    Omidyan, R
    Prince, K C
    Richter, R
    Söderström, J
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Stranges, S
    Tabrizchi, M
    Åœitnik, M
    Angular effects in autoionization of 3 P doubly excited states in He2009In: Journal of Physics: Conference Series, Vol. 194Article in journal (Refereed)
    Abstract [en]

    The first members of dipole allowed 3 P o doubly excited series in helium have been observed in resonant photoexcitation of 1 s 2 s 3 S e metastable atoms. A good agreement measured relative photoionization cross sections is achieved when theory includes the radiation damping and, also important, the effects of spin-orbit multiplet splitting on electron angular distribution.

  • 17. Alagia, M
    et al.
    Coreno, M
    Farrokhpour, H
    Franceschi, P
    Mihelič, A
    Moise, A
    Omidyan, R
    Prince, K C
    Richter, R
    Söderström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Stranges, S
    Tabrizchi, M
    Åœitnik, M
    Angular effects in autoionization of 3 P doubly excited states in He2009In: Journal of Physics: Conference Series, Vol. 194, no 2Article in journal (Refereed)
    Abstract [en]

    The first members of dipole allowed 3 P o doubly excited series in helium have been observed in resonant photoexcitation of 1 s 2 s 3 S e metastable atoms. A good agreement measured relative photoionization cross sections is achieved when theory includes the radiation damping and, also important, the effects of spin-orbit multiplet splitting on electron angular distribution.

  • 18. Alagia, M.
    et al.
    Coreno, M.
    Farrokhpour, H.
    Franceschi, P.
    Mihelič, A.
    Moise, A.
    Omidyan, R.
    Prince, K.C.
    Richter, R.
    Söderström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Stranges, S.
    Tabrizchi, M.
    Žitnik, M.
    Excitation of 1S and 3S Metastable Helium Atoms to Doubly Excited States2009In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 102, no 15, p. 153001-Article in journal (Refereed)
    Abstract [en]

    We present spectra of triplet and singlet metastable helium atoms resonantly photoexcited to doubly excited states. The first members of three dipole-allowed 1,3Po series have been observed and their relative photoionization cross sections determined, both in the triplet (from 1s2s 3Se) and singlet (from 1s2s 1Se) manifolds. The intensity ratios are drastically different with respect to transitions from the ground state. When radiation damping is included the results for the singlets are in agreement with theory, while for triplets spin-orbit interaction must also be taken into account.

  • 19.
    Alfredsson, Ylvi
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Åhlund, John
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Nilson, Katharina
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Kjeldgaard, Lisbeth
    O'Shea, James
    Theobald, J
    Bao, Zhuo
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Mårtensson, Nils
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Sandell, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Puglia, Carla
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Siegbahn, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Phase and molecular orientation in metal-free phthalocyanine films on conducting glass: Characterization of two deposition methods2005In: Thin Solid Films, Vol. 493, no 1-2, p. 13-19Article in journal (Refereed)
  • 20.
    Alippi, Paola
    et al.
    CNR ISM, Ist Struttura Mat Consiglio Nazl Ric, Via Salaria,Km 29-300, I-00015 Rome, Italy..
    Lanzilotto, Valeria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. CNR IOM, Lab Nazl TASC, C Area Sci Pk SS14 Km 163-5, I-34129 Trieste, Italy.;Univ Trieste, Dept Phys, Via Valerio 2, I-34127 Trieste, Italy..
    Paoletti, Anna Maria
    CNR ISM, Ist Struttura Mat Consiglio Nazl Ric, Via Salaria,Km 29-300, I-00015 Rome, Italy..
    Mattioli, Giuseppe
    CNR ISM, Ist Struttura Mat Consiglio Nazl Ric, Via Salaria,Km 29-300, I-00015 Rome, Italy..
    Zanotti, Gloria
    CNR ISM, Ist Struttura Mat Consiglio Nazl Ric, Via Salaria,Km 29-300, I-00015 Rome, Italy..
    Pennesi, Giovanna
    CNR ISM, Ist Struttura Mat Consiglio Nazl Ric, Via Salaria,Km 29-300, I-00015 Rome, Italy..
    Filippone, Francesco
    CNR ISM, Ist Struttura Mat Consiglio Nazl Ric, Via Salaria,Km 29-300, I-00015 Rome, Italy..
    Cossaro, Albano
    CNR IOM, Lab Nazl TASC, C Area Sci Pk SS14 Km 163-5, I-34129 Trieste, Italy..
    Verdini, Alberto
    CNR IOM, Lab Nazl TASC, C Area Sci Pk SS14 Km 163-5, I-34129 Trieste, Italy..
    Morgante, Alberto
    CNR IOM, Lab Nazl TASC, C Area Sci Pk SS14 Km 163-5, I-34129 Trieste, Italy.;Univ Trieste, Dept Phys, Via Valerio 2, I-34127 Trieste, Italy..
    Bonapasta, Aldo Amore
    CNR ISM, Ist Struttura Mat Consiglio Nazl Ric, Via Salaria,Km 29-300, I-00015 Rome, Italy..
    A Ru-Ru pair housed in ruthenium phthalocyanine: the role of a "cage" architecture in the molecule coupling with the Ag(111) surface2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 2, p. 1449-1457Article in journal (Refereed)
    Abstract [en]

    A number of studies have investigated the properties of monomeric and double-decker phthalocyanines (Pcs) adsorbed on metal surfaces, in view of applications in spintronics devices. In a combined experimental and theoretical study, we consider here a different member of the Pcs family, the (RuPc)(2) dimer, whose structure is characterized by two paired up magnetic centers embedded in a double-decker architecture. For (RuPc)(2) on Ag(111), we show that this architecture works as a preserving cage by shielding the Ru-Ru pair from a direct interaction with the surface atoms. In fact, while noticeable surface-to-molecule charge transfer occurs with the ensuing quenching of the molecular magnetic moment, such phenomena occur here in the absence of a direct Ru-Ag coupling or structural rearrangement, at variance with other Pcs and thanks to the above shielding effect. These unique properties of the (RuPc)(2) architecture are expected to permit an easy control of the surface-to-molecule charge-transfer process as well as of the molecular magnetic properties, thus making the (RuPc)(2) dimer a significant paradigm for innovative "cage" structures as well as a promising candidate for applications in spintronics nano or single-molecule devices.

  • 21.
    Allum, Felix
    et al.
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Burt, Michael
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Amini, Kasra
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Boll, Rebecca
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Kockert, Hansjochen
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Olshin, Pavel K.
    St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia.
    Bari, Sadia
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Bomme, Cedric
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Brausse, Felix
    Max Born Inst, Max Born Str 2A, D-12489 Berlin, Germany.
    de Miranda, Barbara Cunha
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Duesterer, Stefan
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Erk, Benjamin
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Geleoc, Marie
    Univ Paris Saclay, LIDYL, CEA, CNRS,CEA Saclay, F-91191 Gif Sur Yvette, France.
    Geneaux, Romain
    Univ Paris Saclay, LIDYL, CEA, CNRS,CEA Saclay, F-91191 Gif Sur Yvette, France.
    Gentleman, Alexander S.
    Univ Oxford, Phys & Theoret Chem Lab, Dept Chem, Oxford OX1 3QZ, England.
    Goldsztejn, Gildas
    Max Born Inst, Max Born Str 2A, D-12489 Berlin, Germany.
    Guillemin, Renaud
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Holland, David M. P.
    Daresbury Lab, Warrington WA4 4AD, Cheshire, England.
    Ismail, Iyas
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Johnsson, Per
    Lund Univ, Dept Phys, S-22100 Lund, Sweden.
    Journel, Loic
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Kuepper, Jochen
    Deutsch Elektronen Synchrotron DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany;Univ Hamburg, Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany;Univ Hamburg, Dept Chem, Martin Luther King Pl 6, D-20146 Hamburg, Germany.
    Lahl, Jan
    Lund Univ, Dept Phys, S-22100 Lund, Sweden.
    Lee, Jason W. L.
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Maclot, Sylvain
    Lund Univ, Dept Phys, S-22100 Lund, Sweden.
    Mackenzie, Stuart R.
    Univ Oxford, Phys & Theoret Chem Lab, Dept Chem, Oxford OX1 3QZ, England.
    Manschwetus, Bastian
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Mereshchenko, Andrey S.
    St Petersburg State Univ, 7-9 Univ Skaya Nab, St Petersburg 199034, Russia.
    Mason, Robert
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Palaudoux, Jerome
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Piancastelli, Maria Novella
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Penent, Francis
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Rompotis, Dimitrios
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany;European XFEL, Holzkoppel 4, D-22869 Schenefeld, Germany.
    Rouzee, Arnaud
    Max Born Inst, Max Born Str 2A, D-12489 Berlin, Germany.
    Ruchon, Thierry
    Univ Paris Saclay, LIDYL, CEA, CNRS,CEA Saclay, F-91191 Gif Sur Yvette, France.
    Rudenko, Artem
    Kansas State Univ, Dept Phys, JR Macdonald Lab, Manhattan, KS 66506 USA.
    Savelyev, Evgeny
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Simon, Marc
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Schirmel, Nora
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Stapelfeldt, Henrik
    Aarhus Univ, Dept Chem, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
    Techert, Simone
    Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany;Max Planck Inst Biophys Chem, D-37077 Gottingen, Germany;Univ Gottingen, Inst Xray Phys, D-37077 Gottingen, Germany.
    Travnikova, Oksana
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Trippel, Sebastian
    Deutsch Elektronen Synchrotron DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany;Univ Hamburg, Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany.
    Underwood, Jonathan G.
    UCL, Dept Phys & Astron, London WC1E 6BT, England.
    Vallance, Claire
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Wiese, Joss
    Deutsch Elektronen Synchrotron DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany;Univ Hamburg, Dept Chem, Martin Luther King Pl 6, D-20146 Hamburg, Germany.
    Ziaee, Farzaneh
    Kansas State Univ, Dept Phys, JR Macdonald Lab, Manhattan, KS 66506 USA.
    Brouard, Mark
    Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England.
    Marchenko, Tatiana
    Sorbonne Univ, LCPMR, CNRS, F-75005 Paris, France.
    Rolles, Daniel
    Kansas State Univ, Dept Phys, JR Macdonald Lab, Manhattan, KS 66506 USA.
    Coulomb explosion imaging of CH3I and CH2CII photodissociation dynamics2018In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 149, no 20, article id 204313Article in journal (Refereed)
    Abstract [en]

    The photodissociation dynamics of CH3I and CH2CII at 272 nm were investigated by time-resolved Coulomb explosion imaging, with an intense non-resonant 815nmprobe pulse. Fragment ion momenta over a widem/z range were recorded simultaneously by coupling a velocity map imaging spectrometer with a pixel imaging mass spectrometry camera. For both molecules, delay-dependent pump-probe features were assigned to ultraviolet-induced carbon-iodine bond cleavage followed by Coulomb explosion. Multi-mass imaging also allowed the sequential cleavage of both carbon-halogen bonds in CH2ClI to be investigated. Furthermore, delay-dependent relative fragment momenta of a pair of ions were directly determined using recoil-frame covariance analysis. These results are complementary to conventional velocity map imaging experiments and demonstrate the application of time-resolved Coulomb explosion imaging to photoinduced real-time molecular motion.

  • 22. Amft, M.
    et al.
    Walle, L. E.
    Ragazzon, Davide
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Borg, A.
    Uvdal, P.
    Skorodumova, Natalia V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Sandell, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    A Molecular Mechanism for the Water-Hydroxyl Balance during Wetting of TiO22013In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 117, no 33, p. 17078-17083Article in journal (Refereed)
    Abstract [en]

    We show that the formation of the wetting layer and the experimentally observed continuous shift of the H2O-OH balance toward molecular water at increasing coverage on a TiO2(110) surface can be rationalized on a molecular level. The mechanism is based on the initial formation of stable hydroxyl pairs, a repulsive interaction between these pairs, and an attractive interaction with respect to water molecules. The experimental data are obtained by synchrotron radiation photoelectron spectroscopy and interpreted with the aid of density functional theory calculations and Monte Carlo simulations.

  • 23.
    Amidani, Lucia
    et al.
    European Synchrotron, Rossendorf Beamline ESRF, CS40220, F-38043 Grenoble 9, France;Inst Resource Ecol, HZDR, POB 510119, D-01314 Dresden, Germany.
    Plakhova, Tatiana V.
    Lomonosov Moscow State Univ, Dept Chem, Leninskie Gory 1-3, Moscow 119991, Russia.
    Romanchuk, Anna Yu.
    Lomonosov Moscow State Univ, Dept Chem, Leninskie Gory 1-3, Moscow 119991, Russia.
    Gerber, Evgeny
    European Synchrotron, Rossendorf Beamline ESRF, CS40220, F-38043 Grenoble 9, France;Inst Resource Ecol, HZDR, POB 510119, D-01314 Dresden, Germany;Lomonosov Moscow State Univ, Dept Chem, Leninskie Gory 1-3, Moscow 119991, Russia.
    Weiss, Stephan
    Inst Resource Ecol, HZDR, POB 510119, D-01314 Dresden, Germany.
    Efimenko, Anna
    European Synchrotron, ESRF, CS40220, F-38043 Grenoble 9, France.
    Sahle, Christoph J.
    European Synchrotron, ESRF, CS40220, F-38043 Grenoble 9, France.
    Butorin, Sergei M.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Kalmykov, Stepan N.
    Lomonosov Moscow State Univ, Dept Chem, Leninskie Gory 1-3, Moscow 119991, Russia.
    Kvashnina, Kristina O.
    European Synchrotron, Rossendorf Beamline ESRF, CS40220, F-38043 Grenoble 9, France;Inst Resource Ecol, HZDR, POB 510119, D-01314 Dresden, Germany.
    Understanding the size effects on the electronic structure of ThO2 nanoparticles2019In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 20, p. 10635-10643Article in journal (Refereed)
    Abstract [en]

    Developing characterization techniques and analysis methods adapted to the investigation of nanoparticles (NPs) is of fundamental importance considering the role of these materials in many fields of research. The study of actinide based NPs, despite their environmental relevance, is still underdeveloped compared to that of NPs based on stable and lighter elements. We present here an investigation of ThO2 NPs performed with High-Energy Resolution Fluorescence Detected (HERFD) X-ray Absorption Near-Edge Structure (XANES) and with ab initio XANES simulations. The first post-edge feature of Th L-3 edge HERFD XANES disappears in small NPs and simulations considering non-relaxed structural models reproduce the trends observed in experimental data. Inspection of the simulations of Th atoms in the core and on the surface of the NP indeed demonstrates that the first post-edge feature is very sensitive to the lowering of the number of coordinating atoms and therefore to the more exposed Th atoms at the surface of the NP. The sensitivity of the L-3 edge HERFD XANES to low coordinated atoms at the surface stems from the hybridization of the d-Density of States (DOS) of Th with both O and Th neighboring atoms. This may be a common feature to other oxide systems that can be exploited to investigate surface interactions.

  • 24.
    Andersson, J.
    et al.
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden.
    Beerwerth, R.
    Helmholtz Inst Jena, D-07743 Jena, Germany;Friedrich Schiller Univ Jena, Theoret Phys Inst, D-07743 Jena, Germany.
    Roos, A. Hult
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden.
    Squibb, R. J.
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden.
    Singh, R.
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden.
    Zagorodskikh, Sergey
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden.
    Talaee, O.
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden;Univ Oulu, Nano & Mol Syst Res Unit, POB 3000, FI-90014 Oulu, Finland.
    Koulentianos, D.
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden;UPMC Univ Paris 6, Sorbonne Univ, UMR7614, Lab Chim Phys Matiere & Rayonnement, F-75005 Paris, France.
    Eland, J. H. D.
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden;Univ Oxford, Dept Chem, Phys & Theoret Chem Lab, South Parks Rd, Oxford OX1 3QZ, England.
    Fritzsche, S.
    Helmholtz Inst Jena, D-07743 Jena, Germany;Friedrich Schiller Univ Jena, Theoret Phys Inst, D-07743 Jena, Germany.
    Feifel, R.
    Univ Gothenburg, Dept Phys, Origovagen 6B, SE-41258 Gothenburg, Sweden.
    Auger decay of 4d inner-shell holes in atomic Hg leading to triple ionization2017In: Physical Review A: covering atomic, molecular, and optical physics and quantum information, ISSN 2469-9926, E-ISSN 2469-9934, Vol. 96, no 1, article id 012505Article in journal (Refereed)
    Abstract [en]

    Formation of triply ionized states upon the creation of 4d inner-shell holes in atomic Hg is investigated by using synchrotron radiation of 730 eV photon energy and a versatile multielectron coincidence detection technique in combination with multiconfiguration Dirac-Fock calculations. By carefully selecting Coster-Kronig electrons detected only in coincidence with a 4d photoelectron, the Coster-Kronig spectrum has been extracted and the corresponding branching ratios of the 4d hole have been determined. The results are found to differ from previously established experimental ratios based on electron impact ionization but to agree now better with theory. We also present an Auger cascade analysis of pathways leading to triply ionized states of atomic Hg upon removal of a 4d inner-shell electron.

  • 25.
    Andersson, T.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Zhang, C.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Björneholm, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Mikkela, M-H
    Oulu Univ, Dept Phys Sci, Box 3000, FI-90014 Oulu, Finland..
    Jankala, K.
    Oulu Univ, Dept Phys Sci, Box 3000, FI-90014 Oulu, Finland..
    Anin, D.
    Oulu Univ, Dept Phys Sci, Box 3000, FI-90014 Oulu, Finland..
    Urpelainen, S.
    Oulu Univ, Dept Phys Sci, Box 3000, FI-90014 Oulu, Finland..
    Huttula, M.
    Oulu Univ, Dept Phys Sci, Box 3000, FI-90014 Oulu, Finland..
    Tchaplyguine, M.
    Lund Univ, Max Lab, Box 118, SE-22363 Lund, Sweden..
    Electronic structure transformation in small bare Au clusters as seen by x-ray photoelectron spectroscopy2017In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 50, no 1, article id 015102Article in journal (Refereed)
    Abstract [en]

    Free bare gold clusters in the size range from few tens to few hundred atoms (<= 1 nm dimensions) have been produced in a beam, and the size-dependent development of their full valence band including the 5d and 6s parts has been mapped 'on the fly' by synchrotron-based photoelectron spectroscopy. The Au 4f core level has been also probed, and the cluster-specific Au 4f ionization energies have been used to estimate the cluster size. The recorded in the present work valence spectra of the small clusters are compared with the spectra of the large clusters (N similar to 10(3)) created by us using a magnetron-based gas aggregation source. The comparison shows a substantially narrower 5d valence band and the decrease in its splitting for gold clusters in the size range of few hundred atoms and below. Our DFT calculations involving the pseudopotential method show that the 5d band width of the ground state increases with the cluster size and by the size N = 20 becomes comparable with the experimental width of the valence photoelectron spectrum. Similar to the earlier observations on supported clusters we interpret our experimental and theoretical results as due to the undercoordination of a large fraction of atoms in the clusters with N similar to 10(2) and below. The consequences of such electronic structure of small gold clusters are discussed in connection with their specific physical and chemical properties related to nanoplasmonics and nanocatalysis.

  • 26.
    Andersson, Tomas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Zhang, Chaofan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Mikkelä, M. -H
    Anin, Dmitri
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Jänkälä, K.
    Tchaplyguine, M.
    Öhrwall, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Huttula, M.
    Mårtensson, Nils
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Svensson, Svante
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Björneholm, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Photon energy influence on valence photoelectron spectra of silver clusters2012In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 388, no 15, p. 152028-Article in journal (Refereed)
    Abstract [en]

    Silver clusters in the size range of ∼102 constituent atoms have been studied using photoelectron spec-troscopy. The 5s and 4d valence bands have been probed with 40 and 60.5 eV photon energies. Differences in the valence band spectral features have been observed and are discussed in view of earlier results on copper clusters and in terms of differences in mean free path for electrons of different energies.

  • 27.
    André, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Benchmarking Physical Properties of Water Models2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

        Water is a fundamental part of life as we know it, and by that also a fundamental for biology, chemistry, and parts of physics. Understanding how water behaves and interacts is key in many fields of all these three branches of science. Numerical simulation using molecular dynamics can aid in building insight in the behavior and interactions of water. In this thesis molecular dynamics is used to simulate common rigid 3 point water models to see how well they replicate certain physical and chemical properties as functions of temperature. This is done with molecular dynamics program GROMACS which offers a complete set of tools to run simulations and analyze results. Everything has been automated to work with a python script and a file of input parameters. Most of the models follow the same trends and are valid within a limited temperature range.

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  • 28. Angel Nino, Miguel
    et al.
    Kowalik, Iwona Agnieszka
    Jesus Luque, Francisco
    Arvanitis, Dimitri
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Miranda, Rodolfo
    Jose de Miguel, Juan
    Enantiospecific Spin Polarization of Electrons Photoemitted Through Layers of Homochiral Organic Molecules2014In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 26, no 44, p. 7474-7479Article in journal (Refereed)
  • 29.
    Anil Kumar, Puri
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics. Indian Assoc Cultivat Sci, Sch Mat Sci, Kolkata 700032, India..
    Nag, Abhishek
    Indian Assoc Cultivat Sci, Sch Mat Sci, Kolkata 700032, India..
    Mathieu, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Das, Ranjan
    Indian Inst Sci, Solid State & Struct Chem Unit, Bengaluru 560012, India..
    Ray, Sugata
    Indian Assoc Cultivat Sci, Sch Mat Sci, Kolkata 700032, India..
    Nordblad, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Hossain, Akmal
    Indian Inst Sci, Solid State & Struct Chem Unit, Bengaluru 560012, India..
    Cherian, Dona
    Indian Inst Sci, Solid State & Struct Chem Unit, Bengaluru 560012, India..
    Venero, Diego Alba
    ISIS Neutron & Muon Source, STFC Rutherford Appleton Lab, Didcot OX11 OQX, England..
    DeBeer-Schmitt, Lisa
    Oak Ridge Natl Lab, Large Scale Struct Grp, Neutron Sci Directorate, Oak Ridge, TN 37831 USA..
    Karis, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Sarma, D. D.
    Indian Inst Sci, Solid State & Struct Chem Unit, Bengaluru 560012, India..
    Magnetic polarons and spin-glass behavior in insulating La1-xSrxCoO3 (x = 0.125 and 0.15)2020In: Physical Review Research, E-ISSN 2643-1564, Vol. 2, no 4, article id 043344Article in journal (Refereed)
    Abstract [en]

    The evolution of magnetic polarons in Sr doped LaCoO3 (La1-xSrxCoO3) single crystal and polycrystalline samples are investigated by employing dc and ac magnetic measurement and small angle neutron scattering (SANS) techniques. The effect of magnetic field and temperature on magnetic polarons is experimentally studied for La0.875Sr0.125CoO3 and La0.85Sr0.15CoO3 compounds that belong to the spin glass insulating regime of the broader compositional phase diagram of this system. Langevin analyses of the isothermal magnetization curves in the notional paramagnetic regime prove the existence of magnetic polarons with large moments. The dc field superimposed ac susceptibility data and the analysis of the glassy dynamics prove that the size of polarons in 15% Sr doped crystal increase as the field is increased while the field effect is not visible in the 12.5% Sr doped crystal. A polycrystalline sample of La0.85Sr0.15CoO3 is analyzed by SANS experiments, which confirm nonzero correlation length at temperatures far above the macroscopic ordering temperature and hence the presence of magnetic polarons.

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  • 30. Arion, Tiberiu
    et al.
    Puettner, Ralph
    Lupulescu, Cosmin
    Ovsyannikov, Ruslan
    Förstel, Marko
    Öhrwall, Gunnar
    Lindblad, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Surface and Interface Science.
    Ueda, Kiyoshi
    Svensson, Svante
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Bradshaw, Alex M.
    Eberhardt, Wolfgang
    Hergenhahn, Uwe
    New insight into the Auger decay process in O-2: The coincidence perspective2012In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 185, no 8-9, p. 234-243Article in journal (Refereed)
    Abstract [en]

    Photoelectron-Auger electron coincidence spectroscopy is a powerful tool for the investigation of Auger decay processes with different core-ionized intermediate states. In this paper we describe an investigation into the Auger decay of the O-2 molecule, with the purpose of bringing new insight into the dynamics of the core hole decay mechanism. Using a novel experimental approach to measuring such coincidence spectra we report the highest resolution Auger spectrum of O-2 recorded hitherto. In our approach, we have combined the advantages of these coincidence spectra with the high resolution and excellent signal-to-noise ratios of non-coincident Auger spectra and a state-of-the-art fit analysis. In this way we have derived information about the potential energy curves of the final states W-3 Delta(u), B-3 Pi(g), and B' (3)Sigma(-)(u) and concluded that the corresponding Auger transitions are formed to a large part by strongly overlapping vibrational progressions. The present findings are compared to earlier results reported in the literature confirming some theoretical predictions.

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  • 31.
    Arul Murugan, N.
    et al.
    KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Dept Theoret Chem & Biol, S-10691 Stockholm, Sweden.
    Zalesny, Robert
    Wroclaw Univ Sci & Technol, Fac Chem, Dept Phys & Quantum Chem, Wyb Wyspianskiego 27, PL-50370 Wroclaw, Poland.
    Ågren, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Dept Theoret Chem & Biol, S-10691 Stockholm, Sweden.
    Unusual binding-site-specific photophysical properties of a benzothiazole-based optical probe in amyloid beta fibrils2018In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, no 31, p. 20334-20339Article in journal (Refereed)
    Abstract [en]

    Optical imaging of amyloid fibrils serves as a cost-effective route for the diagnosis of Alzheimer-like conformational diseases. However{,} the challenge here is to optimize the binding affinity and photophysical properties of the optical imaging agents in a way specific to certain types of amyloids. In a few occasions it is shown that novel optical imaging agents can be designed to bind to a particular type of amyloid fibril with larger binding affinity and specificity. There is also a recent report on photoluminescent polythiophenes which display photophysical properties that can be used to distinguish the variants or subtypes of amyloids (J. Rasmussen et al.{,} Proc. Natl. Acad. Sci. U. S. A.{,} 2017{,} 114(49){,} 13018–13023). Based on a multiscale modeling approach{,} here{,} we report on the complementary aspect that the photophysical properties of a benzothiazole based optical probe (referred to as BTA-3) can be specific to the binding sites in the same amyloid fibrils and we attribute this to its varying electronic structure in different sites. As reported experimentally from competitive binding assay studies for many amyloid staining molecules and tracers{,} we also show multiple binding sites in amyloid fibrils for this probe. In particular{,} BTA-3 displayed a red-shift in its low-frequency absorption band only in site-4{,} a surface site of amyloid fibrils when compared to the spectra in water solvent. In the remaining sites{,} it exhibited a less significant blue shift for the same absorption band.

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  • 32.
    Arvanitis, Dimitri
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Sanyal, Biplab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Eriksson, Olle
    Nordström, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Karis, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Arvanitis, Dimitri
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Konishi, Takehisa
    Holub Krappe, Elisabeth
    Hunter Dunn, Jonathan
    Influence of ligand states on the relationship between orbital moment and magnetocrystalline anisotropy2007In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 99, no 17, p. 177207-Article in journal (Refereed)
    Abstract [en]

    The spin and orbital moments of Au/Co/Au trilayers grown on a W(110) single crystal substrate have been investigated by means of x-ray magnetic circular dichroism. Our findings suggest that the orbital moment of Co does not obtain a maximum value along the easy axis, in contrast with previous experience. This is attributed to the large spin-orbit interaction within the Au caps. Both second order perturbation theory and first principles calculations show how the magnetocrystalline anisotropy (MCA) is dramatically influenced by this effect, and how this leads to the fact that the orbital moment anisotropy is not proportional to the MCA.

  • 33.
    Ashraf, Shakeel
    et al.
    Mid Sweden Univ, Dept Elect Design, Sundsvall, Sweden..
    Mattsson, Claes G.
    Mid Sweden Univ, Dept Elect Design, Sundsvall, Sweden..
    Fondell, Mattis
    Helmholtz Zentrum, Inst Methods & Instrumentat Synchrotron Radiat Re, Berlin, Germany..
    Lindblad, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Thungström, Göran
    Mid Sweden Univ, Dept Elect Design, Sundsvall, Sweden..
    Surface modification of SU-8 for metal/SU-8 adhesion using RF plasma treatment for application in thermopile detectors2015In: Materials Research Express, E-ISSN 2053-1591, Vol. 2, no 8, article id 086501Article in journal (Refereed)
    Abstract [en]

    This article reports on plasma treatment of SU-8 epoxy in order to enhance adhesive strength for metals. Its samples were fabricated on standard silicon wafers and treated with (O-2 and Ar) RF plasma at a power of 25 W at a low pressure of (3 x 10(-3) Torr) for different time spans (10-70 s). The sample surfaces were characterized in terms of contact angle, surface (roughness and chemistry) and using a tape test. During the contact angle measurement, it was observed that the contact angle was reduced from 73 degrees to 5 degrees (almost wet) and 23 degrees for (O-2 and Ar) treated samples, respectively. The root mean square surface roughness was significantly increased by 21.5% and 37.2% for (O-2 and Ar) treatment, respectively. A pattern of metal squares was formed on the samples using photolithography for a tape test. An adhesive tape was applied to the samples and peeled off at 180 degrees The maximum adhesion results, more than 90%, were achieved for the O-2-treated samples, whereas the Ar-treated samples showed no change. The XPS study shows the formation of new species in the O-2-treated sample compared to the Ar-treated samples. The high adhesive results were due to the formation of hydrophilic groups and new O-2 species in the O-2-treated samples, which were absent in Ar-treated samples.

  • 34.
    Aung, Su Htike
    et al.
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland;Shwebo Univ, Phys Dept, Shwebo 02261, Myanmar;Univ Mandalay, Dept Phys, Mat Res Lab, Mandalay 05032, Myanmar.
    Zhao, Lichen
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland;Peking Univ, Dept Phys, State Key Lab Artificial Microstruct & Mesoscop P, Beijing 100871, Peoples R China.
    Nonomura, Kazuteru
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Oo, Than Zaw
    Univ Mandalay, Dept Phys, Mat Res Lab, Mandalay 05032, Myanmar.
    Zakeeruddin, Shaik M.
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Vlachopoulos, Nick
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Sloboda, Tamara
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Svanström, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Cappel, Ute B.
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Hagfeldt, Anders
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Graetzel, Michael
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Toward an alternative approach for the preparation of low-temperature titanium dioxide blocking underlayers for perovskite solar cells2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 17, p. 10729-10738Article in journal (Refereed)
    Abstract [en]

    The anodic electrodeposition method is investigated as an alternative technique for the preparation of a titanium oxide (TiO2) blocking underlayer (UL) for perovskite solar cells (PSCs). Extremely thin Ti-IV-based films are grown from aqueous acidic titanium(III) chloride in an electrochemical cell at room temperature. This precursor layer is converted to the UL (ED-UL), in a suitable state for PSC applications, by undertaking a sintering step at 450 degrees C for half an hour. PSCs with the composition of the light-absorbing material FA(0.85)MA(0.10)Cs(0.05)Pb(I0.87Br0.13)(3) (FA and MA denote the formamidinium and methylammonium cations, respectively) based on the ED-UL are compared with PSCs with the UL of a standard type prepared by the spray-pyrolysis method at 450 degrees C from titanium diisopropoxide bis(acetylacetonate) (SP-UL). We obtain power conversion efficiencies (PCEs) of over 20% for mesoscopic perovskite devices employing both ED-ULs and SP-ULs. Slightly higher fill factor values are observed for ED-UL-based devices. In addition, ED-ULs prepared by the same method have also been applied in planar PSCs, resulting in a PCE exceeding 17%, which is comparable to that for similar PSCs with an SP-UL. The preparation of ED-ULs with a lower sintering temperature, 150 degrees C, has also been examined. The efficiency of a planar PSC incorporating this underlayer was 14%. These results point out to the possibility of applying ED-ULs in flexible planar PSCs in the future.

  • 35. Aziz, Emad F
    et al.
    Gråsjö, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Forsberg, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Soft X-Ray Physics.
    Andersson, Egil
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Soft X-Ray Physics.
    Söderström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Duda, Laurent
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Zhang, Wenhua
    Yang, Jinglong
    Eisebitt, Stefan
    Bergström, Christel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Luo, Yi
    Nordgren, Joseph
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Surface and Interface Science.
    Eberhardt, Wolfgang
    Rubensson, Jan-Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Photoinduced Formation of N2 Molecules in Ammonium Compounds2007In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 111, no 39, p. 9662-9669Article in journal (Refereed)
    Abstract [en]

    Via fluorescence yield (FY) and resonant inelastic scattering spectroscopy in the soft X-ray range we find that soft X-rays induce formation of N2 molecules in solid NH4Cl and in related compounds. The nitrogen molecules form weak bonds in NH4Cl, so that a substantial fraction of the molecules remains in the sample. From measurements of the FY as a function of exposure and temperature, the rates for the photochemical processes are estimated. At elevated temperatures (363 K), several nitrogen atoms are removed from the sample per incoming photon. At lower temperatures (233 K), the rate is reduced to around 0.02 nitrogen atoms for each incoming photon. Virtually all these atoms form N2 molecules which are bound in the sample. The generality and implications of these results are briefly discussed.

  • 36. Bailey, W. E.
    et al.
    Cheng, C.
    Knut, Ronny
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Karis, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Auffret, S.
    Zohar, S.
    Keavney, D.
    Warnicke, P.
    Lee, J. -S
    Arena, D. A.
    Detection of microwave phase variation in nanometre-scale magnetic heterostructures2013In: Nature Communications, E-ISSN 2041-1723, Vol. 4, p. 2025-Article in journal (Refereed)
    Abstract [en]

    The internal phase profile of electromagnetic radiation determines many functional properties of metal, oxide or semiconductor heterostructures. In magnetic heterostructures, emerging spin electronic phenomena depend strongly upon the phase profile of the magnetic field (H) over tilde at gigahertz frequencies. Here we demonstrate nanometre-scale, layer-resolved detection of electromagnetic phase through the radio frequency magnetic field (H) over tilde (rf) in magnetic heterostructures. Time-resolved X-ray magnetic circular dichroism reveals the local phase of the radio frequency magnetic field acting on individual magnetizations (M) over tilde (i) through the susceptibility as (M) over tilde = (chi) over tilde(H) over tilde (rf). An unexpectedly large phase variation, similar to 40 degrees, is detected across spin-valve trilayers driven at 3 GHz. The results have implications for the identification of novel effects in spintronics and suggest general possibilities for electromagnetic-phase profile measurement in heterostructures.

  • 37.
    Banerjee, Amitava
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Chakraborty, Sudip
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Rashba Triggered Electronic and Optical Properties in De Novo Designed Mixed Halide Hybrid PerovskitesManuscript (preprint) (Other academic)
  • 38.
    Banerjee, Paramita
    et al.
    Indian Assoc Cultivat Sci, Dept Mat Sci, Kolkata 700032, India..
    Pathak, Biswarup
    Indian Inst Technol, Discipline Chem, Indore 452020, India..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Das, G. P.
    Indian Assoc Cultivat Sci, Dept Mat Sci, Kolkata 700032, India..
    First principles design of Li functionalized hydrogenated h-BN nanosheet for hydrogen storage2016In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, no 32, p. 14437-14446Article in journal (Refereed)
    Abstract [en]

    Employing first principles density functional theory (DFT) based approach, the structure, stability and hydrogen storage efficiency of a hydrogenated hexagonal boron nitride sheet (BHNH chair conformer) functionalized by the lightest alkali metal atom Li has been explored here in details. Substituting one hydrogen atom from both B and N sides of BHNH sheet by a Li atom, we have found that Li becomes cationic and acts as a binding site to adsorb hydrogen molecules. The stability of this Li-substituted BHNH sheet has been indicated via Ab-initio Molecular Dynamics (AIMD) simulation upto 400 K. The binding energy (similar to 0.18-0.3 eV/H-2 molecule) and gravimetric density (similar to 6 wt %) (upto similar to 200 K) of the hydrogen molecules fall in the required window for practical hydrogen storage. AIMD simulation indicates complete dehydrogenation from this system occurs at similar to 400 K, thereby predicting the suitability of this system from the point of view of efficient hydrogen storage.

  • 39.
    Banerjee, S.
    et al.
    Univ Augsburg, Inst Phys, Ctr Elect Correlat & Magnetism, Theoret Phys 3, D-86135 Augsburg, Germany.;KTH Royal Inst Technol, NORDITA, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.;Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.;Royal Inst Technol, Div Theoret Chem & Biol, SE-10691 Stockholm, Sweden..
    Abergel, D. S. L.
    KTH Royal Inst Technol, NORDITA, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.;Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden..
    Ågren, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Royal Inst Technol, Div Theoret Chem & Biol, SE-10691 Stockholm, Sweden..
    Aeppli, G.
    Paul Scherrer Inst, CH-5232 Villigen, Switzerland.;Swiss Fed Inst Technol, Lab Solid State Phys, CH-8093 Zurich, Switzerland.;EPF Lausanne, Inst Phys, CH-1015 Lausanne, Switzerland..
    Balatsky, A. , V
    Interacting Dirac materials2020In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 32, no 40, article id 405603Article in journal (Refereed)
    Abstract [en]

    We investigate the extent to which the class of Dirac materials in two-dimensions provides general statements about the behavior of both fermionic and bosonic Dirac quasiparticles in the interacting regime. For both quasiparticle types, we find common features for the interaction induced renormalization of the conical Dirac spectrum. We perform the perturbative renormalization analysis and compute the self-energy for both quasiparticle types with different interactions and collate previous results from the literature whenever necessary. Guided by the systematic presentation of our results in table1, we conclude that long-range interactions generically lead to an increase of the slope of the single-particle Dirac cone, whereas short-range interactions lead to a decrease. The quasiparticle statistics does not qualitatively impact the self-energy correction for long-range repulsion but does affect the behavior of short-range coupled systems, giving rise to different thermal power-law contributions. The possibility of a universal description of the Dirac materials based on these features is also mentioned.

  • 40. Baryshnikov, Gleb V.
    et al.
    Sunchugashev, Dmitry A.
    Valiev, Rashid R.
    Minaev, Boris F.
    Ågren, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Vibronic absorption spectra of the angular fused bisindolo- and biscarbazoloanthracene blue fluorophores for OLED applications2018In: Chemical Physics, ISSN 0301-0104, E-ISSN 1873-4421, Vol. 513, p. 105-111Article in journal (Refereed)
    Abstract [en]

    An in-depth analysis of the vibronic absorption spectra for the recently synthesized blue-fluorescent OLED emitters bis[(1,2)(5,6)]indoloanthracene and biscarbazolo[3,4-a:3′,4′-h]anthracene has been carried out computationally at the density functional theory level within the Franck-Condon approximation. These molecules are characterized by extended and rich electronic absorption spectra with most absorption bands being of vibronic origin. The first excited singlet state of bis[(1,2)(5,6)]indoloanthracene compound demonstrates a clear observable double-peak vibronic progression for two different active modes in the absorption spectrum, while the S2 state is vibronically inactive. In contrast, for the larger biscarbazolo[3,4-a:3′,4′-h]anthracene compound the S0 → S2 transition demonstrates well-resolved intense vibronic bands which overlap the less intense progressions of few modes in the S0 → S1 transition. We have also found, that even the higher-lying and very intense S0 → S4 and S0 → S5 transitions for bis[(1,2)(5,6)]indoloanthracene and biscarbazolo[3,4-a:3′,4′-h]anthracene, respectively, are characterized by clear vibronic progressions in excellent agreement with experimental spectra.

  • 41.
    Baryshnikov, Glib, V.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Bohdan Khmelnytsky Natl Univ, Dept Chem & Nanomat Sci, UA-18031 Cherkassy, Ukraine..
    Valiev, Rashid R.
    Univ Helsinki, Fac Sci, Dept Chem, FIN-00014 Helsinki, Finland.;Natl Res Tomsk Polytech Univ, Res Sch Chem & Appl Biomed Sci, Tomsk 634050, Russia..
    Nasibullin, Rinat T.
    Tomsk State Univ, Tomsk 634050, Russia..
    Sundholm, Dage
    Univ Helsinki, Fac Sci, Dept Chem, FIN-00014 Helsinki, Finland..
    Kurten, Theo
    Univ Helsinki, Fac Sci, Dept Chem, FIN-00014 Helsinki, Finland..
    Ågren, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Henan Univ, Coll Chem & Chem Engn, Kaifeng 475004, Henan, Peoples R China..
    Aromaticity of Even-Number Cyclo[n]carbons (n=6-100)2020In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 124, no 51, p. 10849-10855Article in journal (Refereed)
    Abstract [en]

    The recently synthesized cyclo[18]carbon molecule has been characterized in a number of studies by calculating electronic, spectroscopic, and mechanical properties. However, cyclo[18] carbon is only one member of the class of cyclo[n]carbons-standalone carbon allotrope representatives. Many of the larger members of this class of molecules have not been thoroughly investigated. In this work, we calculate the magnetically induced current density of cyclo[n]carbons in order to elucidate how electron delocalization and aromatic properties change with the size of the molecular ring (n), where n is an even number between 6 and 100. We find that the Hiickel rules for aromaticity (4k + 2) and antiaromaticity (4k) become degenerate for large C-n rings (n > 50), which can be understood as a transition from a delocalized electronic structure to a nonaromatic structure with localized current density fluxes in the triple bonds. Actually, the calculations suggest that cyclo[n]carbons with n > 50 are nonaromatic cyclic polyalkynes. The influence of the amount of nonlocal exchange and the asymptotic behavior of the exchange-correlation potential of the employed density functionals on the strength of the magnetically induced ring current and the aromatic character of the large cyclo[n]carbons is also discussed.

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  • 42.
    Baryshnikova, Alina T.
    et al.
    Bohdan Khmelnytsky Natl Univ, Dept Chem & Nanomat Sci, UA-18031 Cherkassy, Ukraine.
    Minaev, Boris F.
    Bohdan Khmelnytsky Natl Univ, Dept Chem & Nanomat Sci, UA-18031 Cherkassy, Ukraine.
    Baryshnikov, Gleb, V
    Bohdan Khmelnytsky Natl Univ, Dept Chem & Nanomat Sci, UA-18031 Cherkassy, Ukraine;KTH Royal Inst Technol, Div Theoret Chem & Biol, Sch Engn Sci Chem Biotechnol & Hlth, S-10691 Stockholm, Sweden.
    Ågren, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. KTH Royal Inst Technol, Div Theoret Chem & Biol, Sch Engn Sci Chem Biotechnol & Hlth, S-10691 Stockholm, Sweden.
    Computational study of the structure and magnetic properties of the weakly-coupled tetranuclear square-planar complex of Cu(II) with a tetraporphyrin sheet2019In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 485, p. 73-79Article in journal (Refereed)
    Abstract [en]

    Owing to the fact that weakly-coupled Cu(II) complexes are potentially applicable in the fields of spintronics and single-molecule magnets we have studied one particularly conspicuous case - a tetranuclear square-planar complex of Cu(II) ions with a pi-extended tetraporphyrin ligand (Tetrahedron, 2008, 64, 11433), the structural criteria of which, with very long distances between the paramagnetic centers, can sensibly define the exchange coupling constants and magnetic behaviour. We use the "broken symmetry" density functional theory formalism for various spin states (open-shell singlet, triplet and quintet states). The calculated value of the magnetic exchange integral corresponds to a very weak antiferromagnetic coupling between the neighboring Cu(II) ions (j(calc) = -1.48 cm(-1) (calculated) J(exp) = - 1.16 cm(-1) (experiment)). The opposite Cu(II) ions are coupled ferromagnetically with an extremely small exchange constant (j(calc) = 0.09 cm(-1) (calculated) that corresponds to the open-shell singlet ground state of the following spin configuration vertical bar up arrow down arrow up arrow down arrow >. The exchange mechanism between the [Cu(n) + 4N] localized singly-occupied "magnetic" orbitals of the d(xy) (Cu) + 4sp(2)(N) nature indicates a diffuse non-zero overlap between them on the Carbon atoms of the organic ligand. The numerical analysis of atomic spin densities and corresponding decomposition coefficients for the singly-occupied "magnetic" orbitals confirm the proposed exchange mechanism. This superexchange pathway is mediated by the in-plane sp(2)-hybrid orbitals of the Carbon atoms that couple four [Cu + 4N] fragments by the sigma-bond system. For more detailed characterization of the target system a topological analysis of electron density distributions in the high-spin quintet states has been carried out using the Bader's method "quantum theory of atoms in molecules".

  • 43.
    Baur, Christian
    et al.
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Källquist, Ida
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Chable, Johann
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Chang, Jin Hyun
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Johnsen, Rune E.
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Ruiz-Zepeda, Francisco
    Natl Inst Chem, Hajdrihova 19,POB 660, SI-1000 Ljubljana, Slovenia.
    Ateba Mba, Jean-Marcel
    Natl Inst Chem, Hajdrihova 19,POB 660, SI-1000 Ljubljana, Slovenia.
    Naylor, Andrew J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Garcia-Lastra, Juan Maria
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Vegge, Tejs
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Klein, Franziska
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Schür, Annika R.
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Norby, Poul
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Fichtner, Maximilian
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany;Karlsruhe Inst Technol, Inst Nanotechnol, POB 3640, D-76021 Karlsruhe, Germany.
    Improved cycling stability in high-capacity Li-rich vanadium containing disordered rock salt oxyfluoride cathodes2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 37, p. 21244-21253Article in journal (Refereed)
    Abstract [en]

    Lithium-rich transition metal disordered rock salt (DRS) oxyfluorides have the potential to lessen one large bottleneck for lithium ion batteries by improving the cathode capacity. However, irreversible reactions at the electrode/electrolyte interface have so far led to fast capacity fading during electrochemical cycling. Here, we report the synthesis of two new Li-rich transition metal oxyfluorides Li2V0.5Ti0.5O2F and Li2V0.5Fe0.5O2F using the mechanochemical ball milling procedure. Both materials show substantially improved cycling stability compared to Li2VO2F. Rietveld refinements of synchrotron X-ray diffraction patterns reveal the DRS structure of the materials. Based on density functional theory (DFT) calculations, we demonstrate that substitution of V3+ with Ti3+ and Fe3+ favors disordering of the mixed metastable DRS oxyfluoride phase. Hard X-ray photoelectron spectroscopy shows that the substitution stabilizes the active material electrode particle surface and increases the reversibility of the V3+/V5+ redox couple. This work presents a strategy for stabilization of the DRS structure leading to improved electrochemical cyclability of the materials.

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  • 44.
    Bauters, Stephen
    et al.
    ESRF European Synchrotron, Rossendorf Beamline, CS40220, F-38043 Grenoble 9, France.;Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Scheinost, Andreas C.
    ESRF European Synchrotron, Rossendorf Beamline, CS40220, F-38043 Grenoble 9, France.;Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Schmeide, Katja
    Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Weiss, Stephan
    Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Dardenne, Kathy
    Karlsruhe Inst Technol KIT, Inst Nucl Waste Disposal INE, POB 3640, D-76021 Karlsruhe, Germany..
    Rothe, Jorg
    Karlsruhe Inst Technol KIT, Inst Nucl Waste Disposal INE, POB 3640, D-76021 Karlsruhe, Germany..
    Mayordomo, Natalia
    Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Steudtner, Robin
    Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Stumpf, Thorsten
    Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Abram, Ulrich
    Free Univ Berlin, Inst Chem & Biochem, Fabeckstr 34-36, D-14195 Berlin, Germany..
    Butorin, Sergei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Kvashnina, Kristina O.
    ESRF European Synchrotron, Rossendorf Beamline, CS40220, F-38043 Grenoble 9, France.;Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Signatures of technetium oxidation states: a new approach2020In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 56, no 67, p. 9608-9611Article in journal (Refereed)
    Abstract [en]

    A general strategy for the determination of Tc oxidation state by new approach involving X-ray absorption near edge spectroscopy (XANES) at the Tc L-3 edge is shown. A comprehensive series of Tc-99 compounds, ranging from oxidation states I to VII, was measured and subsequently simulated within the framework of crystal-field multiplet theory. The observable trends in the absorption edge energy shift in combination with the spectral shape allow for a deeper understanding of complicated Tc coordination chemistry. This approach can be extended to numerous studies of Tc systems as this method is one of the most sensitive methods for accurate Tc oxidation state and ligand characterization.

  • 45.
    Belyaev, Andrey K.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Astrophysics.
    Barklem, Paul S.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Guitou, M.
    Spielfiedel, A.
    Feautrier, N.
    Vlasov, D. V.
    Rodionov, D. S.
    Ab initio cross sections for low-energy inelastic Mg+H collisions2012In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 388, no 9, p. 092002-Article in journal (Refereed)
    Abstract [en]

    Full quantum scattering calculations of cross sections for low-energy near-threshold inelastic Mg + H collisions are reported, such processes being of interest for modelling of Mg spectral lines in stellar atmospheres. Nonadiabatic transions associated with radial couplings at avoided ionic crossings in the 2Σ+ molecular states are found to be the main mechanism for excitation and ion-pair production processes.

  • 46.
    Benhouria, Y.
    et al.
    Univ Moulay Ismail, Unite Associee CNRST URAC 08, LP2MS, Phys Dept,Fac Sci, BP 11201, Meknes, Morocco..
    Oubelkacem, A.
    Univ Moulay Ismail, Unite Associee CNRST URAC 08, LP2MS, Phys Dept,Fac Sci, BP 11201, Meknes, Morocco..
    Essaoudi, I.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Univ Moulay Ismail, Unite Associee CNRST URAC 08, LP2MS, Phys Dept,Fac Sci, BP 11201, Meknes, Morocco..
    Ainane, A.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Univ Moulay Ismail, Unite Associee CNRST URAC 08, LP2MS, Phys Dept,Fac Sci, BP 11201, Meknes, Morocco.;Max Planck Inst Phys Complexer Syst, Nothnitzer Str 38, D-01187 Dresden, Germany..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Dynamic Magnetic Properties of a Mixed Spin Ising Double-Walled Ferromagnetic Nanotubes: A Dynamic Monte Carlo Study2017In: Journal of Superconductivity and Novel Magnetism, ISSN 1557-1939, E-ISSN 1557-1947, Vol. 30, no 3, p. 839-844Article in journal (Refereed)
    Abstract [en]

    Using the dynamic Monte Carlo simulation, the dynamic critical temperature of a ferromagnetic or ferrimagnetic double-walled nanotubes (DWNTs) is studied within the kinetic Ising model under the presence of a time-dependent oscillating external magnetic and crystal fields with mixed spins S (A) = 1 and S (B) = 3/2. The effects of the time-dependent oscillating external magnetic field, the period of the oscillating magnetic field, and the crystal field on the thermal behavior of the dynamic sub-lattice order parameters and the total dynamic order parameter, total dynamical magnetic susceptibility, dynamical specific heat, and dynamic hysteresis of a DWNTs are studied. Our theoretical predictions may be a reference for future experiment studies of the nanostructures.

  • 47.
    Berger, Andrew J.
    et al.
    NIST, Quantum Electromagnet Div, Boulder, CO 80305 USA.
    Edwards, Eric R. J.
    NIST, Quantum Electromagnet Div, Boulder, CO 80305 USA.
    Nembach, Hans T.
    NIST, Quantum Electromagnet Div, Boulder, CO 80305 USA.
    Karis, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Weiler, Mathias
    Tech Univ Munich, Phys Dept, D-85748 Garching, Germany;Bayerische Akad Wissensch, Walther Meissner Inst, D-85748 Garching, Germany.
    Silva, T. J.
    NIST, Quantum Electromagnet Div, Boulder, CO 80305 USA.
    Determination of the spin Hall effect and the spin diffusion length of Pt from self-consistent fitting of damping enhancement and inverse spin-orbit torque measurements2018In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 2, article id 024402Article in journal (Refereed)
    Abstract [en]

    Understanding the evolution of spin-orbit torque (SOT) with increasing heavy-metal thickness in ferromagnet/normal metal (FM/NM) bilayers is critical for the development of magnetic memory based on SOT. However, several experiments have revealed an apparent discrepancy between damping enhancement and dampinglike SOT regarding their dependence on NM thickness. Here, using linewidth and phase-resolved amplitude analysis of vector network analyzer ferromagnetic resonance (VNA-FMR) measurements, we simultaneously extract damping enhancement and both fieldlike and dampinglike inverse SOT in Ni80Fe20/Pt bilayers as a function of Pt thickness. By enforcing an interpretation of the data which satisfies Onsager reciprocity, we find that both the damping enhancement and dampinglike inverse SOT can be described by a single spin diffusion length (approximate to 4nm), and that we can separate the spin pumping and spin-memory loss contributions to the total damping. This analysis indicates that less than 40% of the angular momentum pumped by FMR through the Ni80Fe20/Pt interface is transported as spin current into the Pt. On account of the spin-memory loss and corresponding reduction in total spin current available for spin-charge transduction in the Pt, we determine the Pt spin Hall conductivity [sigma(SH) = (2.36 +/- 0.04) x 10(6) omega(-1) m(-1)] and bulk spin Hall angle (theta(SH) = 0.387 +/- 0.008) to be larger than commonly cited values. These results suggest that Pt can be an extremely useful source of SOT if the FM/NM interface can be engineered to minimize spin loss. Lastly, we find that self-consistent fitting of the damping and SOT data is best achieved by a model with Elliott-Yafet spin relaxation and extrinsic inverse spin Hall effect, such that both the spin diffusion length and spin Hall conductivity are proportional to the Pt charge conductivity.

  • 48.
    Bergersen, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    Marinho, R. R. T.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Pokapanich, Wandared
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    Björneholm, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Sæthre, L. J.
    Department of Chemistry, University of Bergen.
    Lindblad, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    Öhrwall, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics V.
    A photoelectron spectroscopic study of aqueous tetrabutylammonium iodide2007In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 19, no 32, p. 326101-Article in journal (Refereed)
    Abstract [en]

    Photoelectron spectra of tetrabutylammonium iodide (TBAI) dissolved in water have been recorded using a novel experimental set-up, which enables photoelectron spectroscopy of volatile liquids. The set-up is described in detail. Ionization energies are reported for I 5p, I 4d, C 1s and N 1s. The C 1s spectrum shows evidence of inelastic scattering of the photoelectrons, that differs from the case of TBAI in formamide.

  • 49.
    Berggren, Elin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Diffusion of Lithium in Boron-doped Diamond Thin Films2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis, the diffusion of lithium was studied on boron-doped diamond (BDD) as a potential anode material in lithium ion batteries (LIB). The initial interaction between deposited lithium and BDD thin films was studied using X-ray Photoelectron Spectroscopy (XPS). Diffusion is directly linked to reactions between lithium and carbon atoms in the BDD-lithium interface. By measuring binding energies of core-electrons of carbon and lithium before and after deposition, these reactions can be analyzed. Scanning Electron Microscopy (SEM) was used to study the BDD surface and the behaviour of deposited lithium. Experiments show that a chemical interaction occurs between lithium and carbon atoms in the surfacelayers of the BDD. The diffusion of lithium is discussed from spectroscopic data and suggests that surface diffusion is occurring and no proof of bulk diffusion was found. The results do not exclude bulk diffusion in later states but it was not found in the initial interaction at the interface after depositing lithium. SEM images show that lithium clusters in the nanometer range are formed on the BDD surface. The results of this study give insights in the initial diffusion behaviour of lithium at the BDD interface and possible following events are discussed.

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    Master Thesis: Elin Berggren
  • 50.
    Bergh, Magnus
    et al.
    Swedish Def Res Agcy, S-16490 Stockholm, Sweden..
    Caleman, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics. DESY, Ctr Free Electron Laser Sci, Hamburg, Germany..
    A Validation Study of the General Amber Force Field Applied to Energetic Molecular Crystals2016In: Journal of Energetic Materials, ISSN 0737-0652, E-ISSN 1545-8822, Vol. 34, no 1, p. 62-75Article in journal (Refereed)
    Abstract [en]

    Molecula dynamics is a well-established tool to computationally study molecules. However, to reach predictive capability at the level required for applied research and design, extensive validation of the available force fields is pertinent. Here we present a study of density, isothermal compressibility and coefficients of thermal expansion of four energetic materials (FOX-7, RDX, CL-20 and HMX) based on molecular dynamics simulations with the General Amber Force Field (GAFF), and compare the results to experimental measurements from the literature. Furthermore, we quantify the accuracy of the calculated properties through hydrocode simulation of a typical impact scenario. We find that molecular dynamics simulations with generic and computationally efficient force fields may be used to understand and estimate important physical properties of nitramine-like energetic materials.

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