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  • 1. 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.

  • 2.
    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.

  • 3. 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.

  • 4.
    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)
  • 5. 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.

  • 6. 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.

  • 7. 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.

  • 8. 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.

  • 9. 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.

  • 10.
    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)
  • 11.
    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.

  • 12. 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.

  • 13.
    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.

  • 14.
    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.

  • 15. 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)
  • 16. 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.

  • 17.
    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.

  • 18.
    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.

  • 19.
    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, 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.

  • 20. 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.

  • 21. 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, ISSN 2041-1723, 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.

  • 22.
    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.

  • 23. 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.

  • 24.
    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.

  • 25.
    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.

  • 26.
    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.

  • 27.
    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.

  • 28.
    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.

  • 29. Berner, G.
    et al.
    Glawion, S.
    Walde, J.
    Pfaff, F.
    Hollmark, H.M.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Duda, Laurent-Claudius
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Paeterl, S.
    Richter, C.
    Mannhart, J.
    Sing, M.
    Claessen, R.
    LaAlO3/SrTiO3 oxide heterostructures studied by resonant inelastic x-ray scattering2010In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 82, no 24, article id 241405Article in journal (Refereed)
  • 30.
    Bertrand, Philippe
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Doubaji, Siham
    LCME, University Cadi Ayyad, Marrakech, Morocco.
    Saadoune, Ismael
    LCME, University Cadi Ayyad, Marrakech, Morocco.
    Gorgoi, Mihaela
    Helmholtz Zentrum Berlin.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Solhy, Solhy
    Center for Advanced Materials Université Mohammed VI Polytechnique, Lot 660-Hay Moulay Rachid Ben Guerir, Morocco.
    Valvo, Mario
    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.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Passivation Layer and Cathodic Redox Reactions in Sodium-Ion Batteries Probed by HAXPES  2017Conference paper (Other academic)
    Abstract [en]

    In this presentation, we will present a recent example on electrode/electrolyte interfaces of materials for energy storage devices using hard X-rays photoelectron spectroscopy (HAXPES). A nondestructive analysis was made through the electrode/electrolyte interface of the first electrochemical cycle to ensure access to information not only on the active material, but also on the passivation layer formed at the electrode surface and referred to as the solid permeable interface (SPI). [1]

     

    While electrode/electrolyte study has been performed widely on Li-ion battery, not so much attention as been addressed to the Na-ion technology so far. We will focus in this presentation to NaxCo2/3Mn2/9Ni1/9O2, a novel intercalation material that could be be used as cathode in Na-ion batteries. [2] During a typical charge/discharge cycle (i.e. extraction/insertion of Na+ ions), the oxidation state of the various transition metals in the compound changes in a reversible way. A step by step analysis of the first electrochemical cycle was carried out by HAXPES providing unique information on the oxidation state of Ni, Co and Mn as well as a very interesting insight into the passivation layer present at the surface of the electrode, which results from the degradation of the electrolyte components upon reaction. This investigation shows the role of the SPI and the complexity of the redox reactions. [3]

     

     

    [1] B. Philippe, M. Hahlin, K. Edström, T. Gustafsson, H. Siegbahn, H. Rensmo, J. Electrochem. Soc, 2016, 163, A178-A191

    [2] S. Doubaji, M. Valvo, I. Saadoune, M. Dahbi, K.Edström, J. Power Sources, 2014, 266, 275-281

    [3] S. Doubaji, B. Philippe, I. Saadoune, M. Gorgoi, T. Gustafsson, A. Solhy, M. Valvo, H. Rensmo, K. Edström, ChemSusChem, 2016, 9, 97-108

  • 31.
    Bes, R.
    et al.
    Aalto Univ, Dept Appl Phys, POB 14100, FI-00076 Aalto, Finland.
    Kvashnina, K.
    ESRF European Synchrotron, Rossendorf Beamline, CS40220, F-38043 Grenoble 9, France;Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, POB 510119, D-01314 Dresden, Germany.
    Rossberg, A.
    ESRF European Synchrotron, Rossendorf Beamline, CS40220, F-38043 Grenoble 9, France;Helmholtz Zentrum Dresden Rossendorf HZDR, Inst Resource Ecol, POB 510119, D-01314 Dresden, Germany.
    Dottavio, G.
    CEA, DEN, DEC, F-13108 St Paul Les Durance, France.
    Desgranges, L.
    CEA, DEN, DEC, F-13108 St Paul Les Durance, France.
    Pontillon, Y.
    CEA, DEN, CAD, DEC,SA3C,LAMIR, St Paul Les Durance, France.
    Solari, P. L.
    Synchrotron SOLEIL, Ligne Lumiere MARS, BP 48, F-91192 Gif Sur Yvette, France.
    Butorin, Sergei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Martin, P.
    CEA, Res Dept Min & Fuel Recycling Proc, Nucl Energy Div, SFMA,LCC, Bagnols Sur Ceze, France.
    New insight in the uranium valence state determination in UyNd1-yO2 +/- x2018In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 507, p. 145-150Article in journal (Refereed)
    Abstract [en]

    The charge compensation mechanisms in UyNd1-yO2 +/- x, and its consequence on the overall O stoichiometry (or O/M ratio where M = Nd + U) have been studied through the uranium valence state mixture evolution as a function of Nd content up to y = 0.62 by means of high energy resolution fluorescence detection X-ray absorption spectroscopy (HERFD-XAS) at the U M-4-edge. Our results clearly demonstrate the formation of U5+ at low Nd content (y < 0.15). Upon increasing the Nd content, oxygen vacancies and the formation of U6+ appear as competing mechanisms for intermediate Nd concentrations, leading to the co-existence of U4+/U5+/U6+ mixed valence and an overall hypostoichiometry (O/M < 2.00). Finally, the formation of U6+ associated with strongly distorted U local environment is observed for high Nd concentrations (y = 0.62), leading to an overall hyperstoichiometry (O/M < 2.00).

  • 32.
    Beyerlein, Kenneth
    et al.
    Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Hamburg, Germany.
    Jönsson, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Alonso-Mori, Roberto
    SLAC National Accelerator Laboratory, USA.
    Aquila, Andrew
    SLAC National Accelerator Laboratory, USA.
    Bajt, Sasa
    Photon Science, DESY, Hamburg, Germany.
    Barty, Anton
    Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Hamburg, Germany.
    Bean, Richard
    Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Hamburg, Germany.
    Koglin, Jason E.
    SLAC National Accelerator Laboratory, USA.
    Messerschmidt, Marc
    SLAC National Accelerator Laboratory, USA.
    Ragazzon, Davide
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Soklaras, Dimosthenis
    SLAC National Accelerator Laboratory, USA.
    Williams, Garth J.
    SLAC National Accelerator Laboratory, USA.
    Hau-Riege, Stefan
    Lawrence Livermore National Laboratory, USA.
    Boutet, Sebastien
    SLAC National Accelerator Laboratory, USA.
    Chapman, Henry N.
    Center for Free-Electron Laser Science,Deutsches Elektronen-Synchrotron, Hamburg, Germany; Department of Physics, University of Hamburg, Hamburg, Germany; Centre for Ultrafast Imaging, University of Hamburg, Hamburg, Germany .
    Timneanu, Nicusor
    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, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Caleman, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Center for Free-Electron Laser Science,Deutsches Elektronen-Synchrotron, Hamburg, Germany.
    Ultrafast non-thermal heating of water initiated by an X-ray laser2018In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 115, no 22, p. 5652-5657Article in journal (Refereed)
    Abstract [en]

    X-ray Free-Electron Lasers have opened the door to a new era in structural biology, enabling imaging of biomolecules and dynamics that were impossible to access with conventional methods. A vast majority of imaging experiments, including Serial Femtosecond Crystallography, use a liquid jet to deliver the sample into the interaction region. We have observed structural changes in the carrying water during X-ray exposure, showing how it transforms from the liquid phase to a plasma. This ultrafast phase transition observed in water provides evidence that any biological structure exposed to these X-ray pulses is destroyed during the X-ray exposure.The bright ultrafast pulses of X-ray Free-Electron Lasers allow investigation into the structure of matter under extreme conditions. We have used single pulses to ionize and probe water as it undergoes a phase transition from liquid to plasma. We report changes in the structure of liquid water on a femtosecond time scale when irradiated by single 6.86 keV X-ray pulses of more than 106 J/cm2. These observations are supported by simulations based on molecular dynamics and plasma dynamics of a water system that is rapidly ionized and driven out of equilibrium. This exotic ionic and disordered state with the density of a liquid is suggested to be structurally different from a neutral thermally disordered state.

  • 33.
    Beyerlein, Kenneth R.
    et al.
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Dierksmeyer, Dennis
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Mariani, Valerio
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Kuhn, Manuela
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Sarrou, Iosifina
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Ottaviano, Angelica
    Calif State Univ Northridge, Dept Phys, Northridge, CA 91330 USA..
    Awel, Salah
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany..
    Knoska, Juraj
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22607 Hamburg, Germany..
    Fuglerud, Silje
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Norwegian Univ Sci & Technol, Dept Phys, Trondheim, Norway..
    Jönsson, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Stern, Stephan
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;European Xray Free Elect Laser Facil GmbH XFEL, Schenefeld, Germany..
    Wiedorn, Max O.
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22607 Hamburg, Germany..
    Yefanov, Oleksandr
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Adriano, Luigi
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Bean, Richard
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Burkhardt, Anja
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Fischer, Pontus
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Heymann, Michael
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Horke, Daniel A.
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany..
    Jungnickel, Katharina E. J.
    Univ Oxford, Dept Biochem, Oxford, England..
    Kovaleva, Elena
    SLAC Natl Accelerator Lab, SSRL, Menlo Pk, CA USA..
    Lorbeer, Olga
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Metz, Markus
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Meyer, Jan
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Morgan, Andrew
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Pande, Kanupriya
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Panneerselvam, Saravanan
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Seuring, Carolin
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany..
    Tolstikova, Aleksandra
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Lieske, Julia
    Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Aplin, Steve
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Roessle, Manfred
    Fachhsch Lubeck, Lubeck, Germany..
    White, Thomas A.
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Chapman, Henry N.
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, D-22761 Hamburg, Germany.;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22607 Hamburg, Germany..
    Meents, Alke
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Deutsch Elektronen Synchrotron DESY, Photon Sci, Hamburg, Germany..
    Oberthuer, Dominik
    Deutsch Elektronen Synchrotron DESY, Ctr Free Elect Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Mix-and-diffuse serial synchrotron crystallography2017In: IUCrJ, ISSN 0972-6918, E-ISSN 2052-2525, Vol. 4, no 6, p. 769-777Article in journal (Refereed)
    Abstract [en]

    Unravelling the interaction of biological macromolecules with ligands and substrates at high spatial and temporal resolution remains a major challenge in structural biology. The development of serial crystallography methods at X-ray free-electron lasers and subsequently at synchrotron light sources allows new approaches to tackle this challenge. Here, a new polyimide tape drive designed for mix-and-diffuse serial crystallography experiments is reported. The structure of lysozyme bound by the competitive inhibitor chitotriose was determined using this device in combination with microfluidic mixers. The electron densities obtained from mixing times of 2 and 50 s show clear binding of chitotriose to the enzyme at a high level of detail. The success of this approach shows the potential for high-throughput drug screening and even structural enzymology on short timescales at bright synchrotron light sources.

  • 34.
    Bidermane, Ieva
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Structure and Electronic Properties of Phthalocyanine Films on Metal and Semiconductor Substrates2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The current thesis presents fundamental studies of phthalocyanines (Pcs), a group of organic macro-cycle molecules. The use of phthalocyanine molecular films in devices with a variety of possible technological applications has been the reason of the many studies dedicated to such molecules during the last decades.

    Core and valence photoelectron spectroscopies (PES), X-ray absorption spectroscopy (XAS) and scanning tunneling microscopy (STM) techniques are used to study phthalocyanine molecules in gas phase and adsorbed on gold (111) and silicon Si(100)-2x1 substrates. Density functional theory (DFT) is used to obtain further insights in the electronic structure of the phthalocyanines.

    The aim of our studies is to get a deeper understanding into the molecule-molecule and molecule-substrate interactions, a fundamental requirement for improving the devices based on such molecular materials.

    Gas phase PES and XAS studies and single molecule DFT calculations are performed on the valence band (VB) of iron phthalocyanine (FePc), manganese phthalocyanine (MnPc) and metal-free phthalocyanine (H2Pc). The VB simulations have shown how the metal atom of the Pc influences the inner valence states of the molecules. The HOMO of the H2Pc and FePc is formed by mostly C2p states, whereas the HOMO of MnPc has mainly Mn3d character.

    PES studies of H2Pc on Au(111) have revealed the influence of the surface on the adsorption of the monolayer. XAS studies indicate formation of ordered monolayer with the Pc ligands parallel to the surface and the change of the molecular tilt angle with increasing thicknesses. For LuPc2 adsorbed on Au(111), STM study demonstrates a formation of bilayer instead of a monolayer.

    A comparison between the results of LuPc2 adsorbed on pristine or passivated Si(100)-2x1 confirmes the different reactivities of these surfaces: LuPc2 retains many molecular-like characters, when adsorbed on the innert passivated Si. Instead, on the more reactive pristine Si surface, the spectroscopic results have indicated a more significant interaction, possible hybridization and charge redistribution between the molecules and the surface. Moreover, STM images show a modification of the geometrical shape of the molecules, which are proposed to adsorb in two different geometries on the pristine Si surface.

    List of papers
    1. Experimental and theoretical study of electronic structure of lutetium bi-phthalocyanine
    Open this publication in new window or tab >>Experimental and theoretical study of electronic structure of lutetium bi-phthalocyanine
    Show others...
    2013 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 138, no 23, p. 234701-Article in journal (Refereed) Published
    Abstract [en]

    Using Near Edge X-Ray Absorption Fine Structure (NEXAFS) Spectroscopy, the thickness dependent formation of Lutetium Phthalocyanine (LuPc2) films on a stepped passivated Si(100)2x1 reconstructed surface was studied. Density functional theory (DFT) calculations were employed to gain detailed insights into the electronic structure. Photoelectron spectroscopy measurements have not revealed any noticeable interaction of LuPc2 with the H-passivated Si surface. The presented study can be considered to give a comprehensive description of the LuPc2 molecular electronic structure. The DFT calculations reveal the interaction of the two molecular rings with each other and with the metallic center forming new kinds of orbitals in between the phthalocyanine rings, which allows to better understand the experimentally obtained NEXAFS results. 

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-205011 (URN)10.1063/1.4809725 (DOI)000321012400026 ()
    Available from: 2013-08-13 Created: 2013-08-13 Last updated: 2017-12-06Bibliographically approved
    2. Adsorption and Molecular Orientation of Lutetium bi-Phthalocyanine Adlayers on Pristine Si(100)2x1 Surface
    Open this publication in new window or tab >>Adsorption and Molecular Orientation of Lutetium bi-Phthalocyanine Adlayers on Pristine Si(100)2x1 Surface
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    A combined photoelectron spectroscopy (PES), X-ray absorption spectroscopy (XAS)

    and scanning tunneling microscopy (STM) study has been performed to follow the

    change in adsorption geometry and to characterize the adsorbate interaction with the

    substrate for dierent thicknesses of lutetium biphthalocyanine (LuPc2) adlayers on

    pristine Si(100)-2x1 reconstructed stepped surface. A shift to lower binding energies

    with increasing thickness has been shown. The STM results showed clustering of

    LuPc2 starting from submonolayer coverages and two distinct adsorption types have

    been identied. The STM and PES results have been linked together to propose two

    dierent adsorption types involving a stronger and weaker interaction with the Si

    dangling bonds. A change in average angle of molecules with respect to the normal

    of the surface for increasing thicknesses has been seen from the XAS measurements,

    leading to disordered layers for thicker films.

    Keywords
    silicon, phthalocyanines, photoelectron spectroscopy, scanning tunneling microscopy
    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-217079 (URN)
    Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2014-04-29
    3. Photoelectron and Absorption Spectroscopy Studies of Metal-Free Phthalocyanine on Au(111): Experiment and Theory
    Open this publication in new window or tab >>Photoelectron and Absorption Spectroscopy Studies of Metal-Free Phthalocyanine on Au(111): Experiment and Theory
    Show others...
    2013 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 117, no 14, p. 7018-7025Article in journal (Refereed) Published
    Abstract [en]

    The adsorption of monolayers and multilayers of metal-free phthalocyanine molecules on the Au(111) (root 3 x 22) reconstructed surface has been investigated by X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). Our results for the monolayer show that the molecules are arranged tightly onto the surface with their molecular plane parallel to it. In addition, the X-ray absorption spectra of the monolayer have been modeled by density functional theory, which could enlighten new aspect of the interaction between molecules and substrate. The XAS results evidence that also in the multilayer the molecules keep the orientation with the molecular plane parallel to the surface. These results are discussed in the framework of moleculemolecule/moleculeadsorbate interactions.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-200064 (URN)10.1021/jp307626n (DOI)000317552200015 ()
    Available from: 2013-05-23 Created: 2013-05-20 Last updated: 2017-12-06Bibliographically approved
    4. Formation of Self-organized bi-Layer of LuPc2 Molecules on Gold (111) Surface
    Open this publication in new window or tab >>Formation of Self-organized bi-Layer of LuPc2 Molecules on Gold (111) Surface
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Keywords
    Au(111), phthalocyanines, STM, bi-layer, XPS
    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-217081 (URN)
    Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2014-04-29
    5. Characterization of Gas Phase of Iron Phthalocyanine with X-ray Photoelectron and Absorption Spectroscopies
    Open this publication in new window or tab >>Characterization of Gas Phase of Iron Phthalocyanine with X-ray Photoelectron and Absorption Spectroscopies
    Show others...
    2015 (English)In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 252, no 6, p. 1259-1265Article in journal (Refereed) Published
    Abstract [en]

    Despite the numerous studies dedicated to phthalocyanine molecules adsorbed on surfaces, in monolayer or thin film, very few works have been focused on the characterization of vapors of these molecules. In this article we present the C 1s, N 1s and Fe 2p photoemission results as well as N K-edge X-ray absorption data of iron phthalocyanine (FePc) in gas phase. Presented comparison of X-ray photoelectron spectroscopy and X-ray absorption spectroscopy spectra of FePc films show a great similarity with the gas phase results, confirming the molecular character of thick films. The Fe2p photoemission spectrum of the gas phase FePc, shown for the first time, can be considered as a fingerprint of the Fe(II) ionic state of the central metal of the iron phthalocyanine. The performed multiplet calculations for describing the Fe 2p XP spectrum indicate 3Eg (a1g2eg32g1) state as the most probable ground state for thick film of iron phthalocyanine.

    National Category
    Atom and Molecular Physics and Optics
    Identifiers
    urn:nbn:se:uu:diva-217080 (URN)10.1002/pssb.201451147 (DOI)000355756200010 ()
    Funder
    Swedish Research CouncilCarl Tryggers foundation
    Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2017-12-06Bibliographically approved
    6. Atomic Contributions to the Valence Band Photoelectron Spectra of Metal-free, Iron and Manganese Phthalocyanines
    Open this publication in new window or tab >>Atomic Contributions to the Valence Band Photoelectron Spectra of Metal-free, Iron and Manganese Phthalocyanines
    Show others...
    2015 (English)In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 205, p. 92-97Article, review/survey (Other academic) Published
    Abstract [en]

    The present work reports a photoelectron spectroscopy study of the low-energy region of the valence band of metal-free phthalocyanine (H2Pc) compared with those of iron phthalocyanine (FePc) and manganese phthalocyanine (MnPc). We have analysed in detail the atomic orbital composition of the valence band both experimentally, by making use of the variation in photoionization cross-sections with photon energy, and theoretically, by means of density functional theory. The atomic character of the Highest Occupied Molecular Orbital (HOMO), reflected on the outermost valence band binding energy region, is different for MnPc as compared to the other two molecules. The peaks related to the C 2p contributions, result in the HOMO for H2Pc and FePc and in the HOMO-1 for MnPc as described by the theoretical predictions, in very good agreement with the experimental results. The DFT simulations, discerning the atomic contribution to the density of states, indicate how the central metal atom interacts with the C and N atoms of the molecule, giving rise to different partial and total density of states for these three Pc molecules.

    Keywords
    Valence band; X-ray photoelectron spectroscopy; DFT; Phthalocyanines
    National Category
    Atom and Molecular Physics and Optics
    Identifiers
    urn:nbn:se:uu:diva-217083 (URN)10.1016/j.elspec.2015.09.004 (DOI)000367282400011 ()
    Funder
    Swedish Research CouncilKnut and Alice Wallenberg FoundationCarl Tryggers foundation
    Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2017-12-06Bibliographically approved
  • 35.
    Bidermane, Ieva
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Ahmadi, Sareh
    KTH.
    Grazioli, Cesare
    University of Trieste.
    Bouvet, Marcel
    University of Bourgone.
    Mårtensson, Nils
    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.
    Witkowski, Nadine
    Universite de Pierre et Marie Curie.
    Adsorption and Molecular Orientation of Lutetium bi-Phthalocyanine Adlayers on Pristine Si(100)2x1 SurfaceManuscript (preprint) (Other academic)
    Abstract [en]

    A combined photoelectron spectroscopy (PES), X-ray absorption spectroscopy (XAS)

    and scanning tunneling microscopy (STM) study has been performed to follow the

    change in adsorption geometry and to characterize the adsorbate interaction with the

    substrate for dierent thicknesses of lutetium biphthalocyanine (LuPc2) adlayers on

    pristine Si(100)-2x1 reconstructed stepped surface. A shift to lower binding energies

    with increasing thickness has been shown. The STM results showed clustering of

    LuPc2 starting from submonolayer coverages and two distinct adsorption types have

    been identied. The STM and PES results have been linked together to propose two

    dierent adsorption types involving a stronger and weaker interaction with the Si

    dangling bonds. A change in average angle of molecules with respect to the normal

    of the surface for increasing thicknesses has been seen from the XAS measurements,

    leading to disordered layers for thicker films.

  • 36.
    Bidermane, Ieva
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Brumboiu, Iulia
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.
    Totani, Roberta
    University of L'Aquila.
    Grazioli, Cesare
    University of Trieste.
    Shariati Nilsson, Masumeh Nina
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Herper, Heike
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Eriksson, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Sanyal, Biplab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ressel, B
    Univ Nova Gorica, Ajdovscina 5270, Slovenia.
    de Simone, Monica
    Lozzi, Luca
    University of L'Aquila.
    Brena, Barbara
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.
    Puglia, Carla
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Atomic Contributions to the Valence Band Photoelectron Spectra of Metal-free, Iron and Manganese Phthalocyanines2015In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 205, p. 92-97Article, review/survey (Other academic)
    Abstract [en]

    The present work reports a photoelectron spectroscopy study of the low-energy region of the valence band of metal-free phthalocyanine (H2Pc) compared with those of iron phthalocyanine (FePc) and manganese phthalocyanine (MnPc). We have analysed in detail the atomic orbital composition of the valence band both experimentally, by making use of the variation in photoionization cross-sections with photon energy, and theoretically, by means of density functional theory. The atomic character of the Highest Occupied Molecular Orbital (HOMO), reflected on the outermost valence band binding energy region, is different for MnPc as compared to the other two molecules. The peaks related to the C 2p contributions, result in the HOMO for H2Pc and FePc and in the HOMO-1 for MnPc as described by the theoretical predictions, in very good agreement with the experimental results. The DFT simulations, discerning the atomic contribution to the density of states, indicate how the central metal atom interacts with the C and N atoms of the molecule, giving rise to different partial and total density of states for these three Pc molecules.

  • 37.
    Bidermane, Ieva
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Lüder, Johann
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahmadi, S.
    Materialfysik, KTH-Electrum.
    Grazioli, C.
    CNR-IOM, Laboratorio TASC.
    Bouvet, M.
    Institut de Chimie Moléculaire de l’Université de Bourgogne.
    Brena, Barbara
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Mårtensson, Niklas
    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.
    Witkowski, N.
    Institut des Nanosciences de Paris, UPMC.
    When the Grafting of Double Decker Phthalocyanines on Si(100)-2 × 1 Partly Affects the Molecular Electronic Structure2016In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, no 26, p. 14270-14276Article in journal (Refereed)
    Abstract [en]

    A combined X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and density functional theory (DFT) study has been performed to characterize the adsorbate interaction of lutetium biphthalocyanine (LuPc2) molecules on the Si(100)-2 × 1 surface. Large molecule–substrate adsorption energies are computed and are found to compete with the molecule–molecule interactions of the double decker molecules. A particularly good matching between STM images and computed ones confirms the deformation of the molecule upon the absorption process. The comparison between DFT calculations and XP spectra reveals that the electronic distribution in the two plateaus of the biphthalocyanine are not affected in the same manner upon the adsorption onto the silicon surface. This finding can be of particular importance in the implementation of organic molecules in hybrid devices.

  • 38.
    Bidermane, Ieva
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Lüder, Johann
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Boudet, S.
    Zhang, T.
    Ahmadi, S.
    Grazioli, C.
    Bouvet, M.
    Rusz, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Sanyal, Biplab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Eriksson, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Brena, Barbara
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Puglia, Carla
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Witkowski, N.
    Experimental and theoretical study of electronic structure of lutetium bi-phthalocyanine2013In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 138, no 23, p. 234701-Article in journal (Refereed)
    Abstract [en]

    Using Near Edge X-Ray Absorption Fine Structure (NEXAFS) Spectroscopy, the thickness dependent formation of Lutetium Phthalocyanine (LuPc2) films on a stepped passivated Si(100)2x1 reconstructed surface was studied. Density functional theory (DFT) calculations were employed to gain detailed insights into the electronic structure. Photoelectron spectroscopy measurements have not revealed any noticeable interaction of LuPc2 with the H-passivated Si surface. The presented study can be considered to give a comprehensive description of the LuPc2 molecular electronic structure. The DFT calculations reveal the interaction of the two molecular rings with each other and with the metallic center forming new kinds of orbitals in between the phthalocyanine rings, which allows to better understand the experimentally obtained NEXAFS results. 

  • 39.
    Bidermane, Ieva
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Lüder, Johann
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Totani, Roberta
    University of L'Aquila.
    Grazioli, Cesare
    University of Trieste.
    de Simone, Monica
    Coreno, Marcello
    Kivimäki, Antti
    Åhlund, John
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Lozzi, Luca
    University of L'Aquila.
    Brena, Barbara
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Puglia, Carla
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Characterization of Gas Phase of Iron Phthalocyanine with X-ray Photoelectron and Absorption Spectroscopies2015In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 252, no 6, p. 1259-1265Article in journal (Refereed)
    Abstract [en]

    Despite the numerous studies dedicated to phthalocyanine molecules adsorbed on surfaces, in monolayer or thin film, very few works have been focused on the characterization of vapors of these molecules. In this article we present the C 1s, N 1s and Fe 2p photoemission results as well as N K-edge X-ray absorption data of iron phthalocyanine (FePc) in gas phase. Presented comparison of X-ray photoelectron spectroscopy and X-ray absorption spectroscopy spectra of FePc films show a great similarity with the gas phase results, confirming the molecular character of thick films. The Fe2p photoemission spectrum of the gas phase FePc, shown for the first time, can be considered as a fingerprint of the Fe(II) ionic state of the central metal of the iron phthalocyanine. The performed multiplet calculations for describing the Fe 2p XP spectrum indicate 3Eg (a1g2eg32g1) state as the most probable ground state for thick film of iron phthalocyanine.

  • 40.
    Bidermane, Ieva
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Zhang, Teng
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Latvels, Janis
    Riga Technical University.
    Pudzs, Kaspars
    University of Latvia.
    Bouvet, Marcel
    University of Bourgone.
    Puglia, Carla
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Witkowski, Nadine
    Universite de Pierre et Marie Curie.
    Formation of Self-organized bi-Layer of LuPc2 Molecules on Gold (111) SurfaceManuscript (preprint) (Other academic)
  • 41.
    Bjärnhall Prytz, Nicklas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    The Importance of Radiation Damage for Molecular Reconstruction from FEL Diffraction Experiments2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Serial Femtosecond X-ray crystallography (SFX) is a rapidly growing experimental technique by which the structure of a crystalline sample may be determined. The X- rays arrive at the sample in pulse trains of the order of femtoseconds. Each X-ray pulse train hits a unique crystal at a random orientation and produces a diffraction pattern on the detector and series of patterns is obtained, which is the reason for the denomination "serial". Here, the radiation damage done to a sample during an SFX experiment was studied by simulating diffraction patterns including damage. Throughout, a model reference structure in the form of a reflection list was used to simulate patterns. The aim was to minimise the effects of damage through a correction based on available damage data. Firstly, a simulation case with made-up damage data was performed. The made-up data was used to modify the structure factors such that they would appear damaged. After structural reconstruction, the same data was used to correct for the damage. This was done as a validation of the method pipeline. Secondly, a more realistic case, with actual simulated damage

    data and a distribution of incident intensities was carried out. The expectation value of the distribution was used to correct for damage. It is found for both cases that the damage correction improves the agreement between simulated data and the original model. This is a first step toward successfully correcting for radiation damage which would be a big step forward for SFX. 

  • 42.
    Björklund, Erik
    et al.
    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.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    How the Negative Electrode Influences Interfacial and Electrochemical Properties of LiNi1/3Co1/3Mn1/3O2 Cathodes in Li-Ion Batteries2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 13, p. A3054-A3059Article in journal (Refereed)
    Abstract [en]

    The cycle life of LiNi1/3Co1/3Mn1/3O2 (NMC) based cells are significantly influenced by the choice of the negative electrode. Electrochemical testing and post mortem surface analysis are here used to investigate NMC electrodes cycled vs. either Li-metal, graphite or Li4Ti5O12 (LTO) as negative electrodes. While NMC-LTO and NMC-graphite cells show small capacity fading over 200 cycles, NMC-Li-metal cell suffers from rapid capacity fading accompanied with an increased voltage hysteresis despite the almost unlimited access of lithium. X-ray absorption near edge structure (XANES) results show that no structural degradation occurs on the positive electrode even after >200 cycles, however, X-ray photoelectron spectroscopy (XPS) results shows that the composition of the surface layer formed on the NMC cathode in the NMC-Li-metal cell is largely different from that of the other NMC cathodes (cycled in the NMC-graphite or NMC-LTO cells). Furthermore, it is shown that the surface layer thickness on NMC increases with the number of cycles, caused by continuous electrolyte degradation products formed at the Li-metal negative electrode and then transferred to NMC positive electrode.

  • 43.
    Björklund, Erik
    et al.
    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.
    Brandell, Daniel
    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.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    The influence of counter electrode on the capacity fading in LiNi0.33Mn0.33Co0.33O2-based Li-ion battery cells2017Conference paper (Other academic)
  • 44.
    Björneholm, Olle
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Hansen, Martin H.
    Tech Univ Denmark, DK-2800 Lyngby, Denmark.;Univ Copenhagen, Dept Chem, Univ Pk 5, DK-2100 Copenhagen, Denmark..
    Hodgson, Andrew
    Univ Liverpool, Dept Chem, Liverpool L69 7ZD, Merseyside, England..
    Liu, Li-Min
    UCL, London Ctr Nanotechnol, Thomas Young Ctr, Dept Phys & Astron, London WC1E 6BT, England.;UCL, Dept Chem, London WC1E 6BT, England.;Beijing Computat Sci Res Ctr, Beijing 100193, Peoples R China..
    Limmer, David T.
    Princeton Univ, Princeton Ctr Theoret Sci, Princeton, NJ 08544 USA..
    Michaelides, Angelos
    UCL, London Ctr Nanotechnol, Thomas Young Ctr, Dept Phys & Astron, London WC1E 6BT, England.;UCL, Dept Chem, London WC1E 6BT, England..
    Pedevilla, Philipp
    UCL, London Ctr Nanotechnol, Thomas Young Ctr, Dept Phys & Astron, London WC1E 6BT, England.;UCL, Dept Chem, London WC1E 6BT, England..
    Rossmeisl, Jan
    Univ Copenhagen, Dept Chem, Univ Pk 5, DK-2100 Copenhagen, Denmark..
    Shen, Huaze
    Peking Univ, Int Ctr Quantum Mat, Beijing 100871, Peoples R China.;Peking Univ, Sch Phys, Beijing 100871, Peoples R China..
    Tocci, Gabriele
    UCL, London Ctr Nanotechnol, Thomas Young Ctr, Dept Phys & Astron, London WC1E 6BT, England.;UCL, Dept Chem, London WC1E 6BT, England.;Ecole Polytech Fed Lausanne, Sch Engn, Inst Bioengn & Mat Sci & Engn, Lab Fundamental BioPhoton,Lab Computat Sci & Mode, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci, CH-1015 Lausanne, Switzerland..
    Tyrode, Eric
    KTH Royal Inst Technol, Dept Chem, S-10044 Stockholm, Sweden..
    Walz, Marie-Madeleine
    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, Biology, Department of Cell and Molecular Biology, Computational Biology and Bioinformatics.
    Werner, Josephina
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics. Swedish Univ Agr Sci, Dept Chem & Biotechnol, Box 7015, S-75007 Uppsala, Sweden..
    Bluhm, Hendrik
    Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA..
    Water at Interfaces2016In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 116, no 13, p. 7698-7726Article, review/survey (Refereed)
    Abstract [en]

    The interfaces of neat water and aqueous solutions play a prominent role in many technological processes and in the environment. Examples of aqueous interfaces are ultrathin water films that cover most hydrophilic surfaces under ambient relative humidities, the liquid/solid interface which drives many electrochemical reactions, and the liquid/vapor interface, which governs the uptake and release of trace gases by the oceans and cloud droplets. In this article we review some of the recent experimental and theoretical advances in our knowledge of the properties of aqueous interfaces and discuss open questions and gaps in our understanding.

  • 45.
    Björneholm, Olle
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Werner, Josephina
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Ottosson, Niklas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Öhrwall, Gunnar
    Ekholm, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Winter, Bernd
    Unger, Isaak
    Söderström, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Deeper Insight into Depth-Profiling of Aqueous Solutions Using Photoelectron Spectroscopy2014In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 118, no 50, p. 29333-29339Article in journal (Refereed)
    Abstract [en]

    X-ray photoelectron spectroscopy (XPS) is widely used to probe properties such as molecular stoichiometry, microscopic distributions relative to the surface by so-called "depth-profiling", and molecular orientation. Such studies usually rely on the core-level photoionization cross sections being independent of molecular composition. The validity of this assumption has recently been questioned, as a number of gas-phase molecules have been shown to exhibit photon-energy-dependent nonstochiometric intensity oscillations arising from EXAFS-like modulations of the photoionization cross section. We have studied this phenomenon in trichloroethanol in both gas phase and dissolved in water. The gas-phase species exhibits pronounced intensity oscillations, similar to the ones observed for other gas-phase molecules. These oscillations are also observed for the dissolved species, implying that the effect has to be taken into account when performing depth-profiling experiments of solutions and other condensed matter systems. The similarity between the intensity oscillations for gas phase and dissolved species allows us to determine the photoelectron kinetic energy of maximum surface sensitivity, ~100 eV, which lies in the range of pronounced intensity oscillations.

  • 46. Blomquist, J.
    et al.
    Walle, L. E.
    Uvdal, P.
    Borg, A.
    Sandell, A.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Surface and Interface Science. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Water Dissociation on Single Crystalline Anatase TiO2(001) Studied by Photoelectron Spectroscopy2008In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 112, no 42, p. 16616-16621Article in journal (Refereed)
    Abstract [en]

    The adsorption of water on the anatase TiO2(001)-(4 x 1) surface is studied using synchrotron radiation-excited core level photoelectron spectroscopy. The coverage-dependent adsorption of water at low temperature is monitored and compared to the sequence obtained after heating of a water multilayer. Two adsorption phases of submonolayer coverage can be defined: Phase 1 consists only of dissociated water, observed as OH-groups. This phase is found at low coverage at low temperature (190 K) and is the only state of adsorbed water above similar to 230 K. The saturation coverage of phase 1 is consistent with dissociation on the 4-fold-coordinated Ti ridge atoms of the (4 x 1) surface reconstruction. Phase 2 is found at higher coverage, reached at lower temperature. It consists of a mixture of dissociated and molecular water with a ratio of 1:1 at 170 K. The molecular water is found to bond to the hydroxyl groups. The hydroxyl coverage of phase 2 is approximately 2 times that of phase 1. The results suggest that the OH and H2O species of phase 2 are confined to the ridges of the surface.

  • 47.
    Bolognesi, P.
    et al.
    CNR, Ist Struttura Mat, UOS Montelibretti, Area Ric Roma1, I-00185 Rome, Italy..
    O'Keeffe, P.
    CNR, Ist Struttura Mat, UOS Montelibretti, Area Ric Roma1, I-00185 Rome, Italy..
    Mazza, T.
    European XFEL GmbH, D-22761 Hamburg, Germany..
    Bozek, J.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Coffee, R.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Bostedt, C.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Schorb, S.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Carron, S.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Feifel, Raimund
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Mucke, Melanie
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics. Uppsala Univ, Dept Phys & Astron, SE-75120 Uppsala, Sweden..
    Guehr, M.
    SLAC Natl Accelerator Lab, PULSE, Menlo Pk, CA 94025 USA..
    Sistrunk, E. F.
    SLAC Natl Accelerator Lab, PULSE, Menlo Pk, CA 94025 USA..
    Grilj, J.
    SLAC Natl Accelerator Lab, PULSE, Menlo Pk, CA 94025 USA..
    McFarland, B. K.
    SLAC Natl Accelerator Lab, PULSE, Menlo Pk, CA 94025 USA..
    Koch, M.
    SLAC Natl Accelerator Lab, PULSE, Menlo Pk, CA 94025 USA..
    Larsson, M.
    Univ Stockholm, Dept Phys, S-10691 Stockholm, Sweden..
    Salem, P.
    Univ Stockholm, Dept Phys, S-10691 Stockholm, Sweden..
    Berrah, N.
    Univ Connecticut, Dept Phys, Storrs, CT 06269 USA..
    Fang, L.
    Univ Connecticut, Dept Phys, Storrs, CT 06269 USA..
    Osipov, T.
    Univ Connecticut, Dept Phys, Storrs, CT 06269 USA..
    Murphy, B.
    Univ Connecticut, Dept Phys, Storrs, CT 06269 USA..
    Lucchese, R. R.
    Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA..
    Meyer, M.
    European XFEL GmbH, D-22761 Hamburg, Germany..
    Piancastelli, Maria Novella
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Ueda, K.
    Tohoku Univ, Dept Phys, Sendai, Miyagi 9808577, Japan..
    Mondal, S.
    Tohoku Univ, Dept Phys, Sendai, Miyagi 9808577, Japan..
    Miron, C.
    Synchrotron SOLEIL, F-91192 Gif Sur Yvette, France..
    Richter, R.
    Elettra Sincrotrone Trieste, I-34149 Basovizza, Italy..
    Prince, K. C.
    Elettra Sincrotrone Trieste, I-34149 Basovizza, Italy..
    Takahashi, O.
    Hiroshima Univ, Dept Chem, Hiroshima, Japan..
    Avaldi, L.
    CNR, Ist Struttura Mat, UOS Montelibretti, Area Ric Roma1, I-00185 Rome, Italy.;Elettra Sincrotrone Trieste, I-34149 Basovizza, Italy..
    A study of the dynamical energy flow in uracil2015In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 635, article id 112062Article in journal (Refereed)
    Abstract [en]

    The time resolved photoionization of C 1s in uracil following excitation of the neutral molecule by 260 nm pulses has been studied at LCLS.

  • 48. Bomme, C.
    et al.
    Guillemin, R.
    Sheinerman, S.
    Marin, T.
    Journel, L.
    Marchenko, T.
    Kushawaha, R. K.
    Trcera, N.
    Piancastelli, Maria Novella
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Simon, M.
    Post-collision interaction manifestation in molecular systems probed by photoelectron-molecular ion coincidences2013In: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 46, no 21, p. 215101-Article in journal (Refereed)
    Abstract [en]

    S1s photoionization in carbonyl sulfide (OCS), followed by multiple Auger decay is investigated both experimentally and theoretically, by means of photoelectron-ion coincidences. A strong influence of post-collision interaction is observed in the energy shift and the distortion of the photoelectron spectra. The magnitude of this effect depends on the total charge of the ionic fragments, i.e., on the number of electrons emitted during the decay of the inner vacancy. A satisfactory agreement is found between experiment and theory, which allows us to estimate the lifetimes of the various two-hole states of the intermediate OCS2+ ion.

  • 49.
    Bowen, K. P.
    et al.
    Univ Nevada, Dept Chem & Biochem, Las Vegas, NV 89154 USA..
    Hemmers, O.
    Univ Nevada, Dept Chem & Biochem, Las Vegas, NV 89154 USA..
    Guillemin, R.
    Univ Paris 06, CNRS, Lab Chim Phys Mat & Rayonnement, UMR 7614, Paris 05, France..
    Stolte, W. C.
    Natl Secur Technol LLC NSTec, Livermore Operat, Livermore, CA USA..
    Piancastelli, Maria Novella
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Lindle, D. W.
    Univ Nevada, Dept Chem & Biochem, Las Vegas, NV 89154 USA..
    Nondipole Effects in Chiral Molecules Measured with Linearly Polarized Light2015In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 635, article id 112053Article in journal (Refereed)
    Abstract [en]

    We present the first-ever measurement of nondipole chiral angular distribution parameters for C 1s photoemission from each enantiomer of camphor in the photon energy range 296-343eV using linearly polarized light. The angular distribution parameters are determined to be enantiomer-specific, suggesting a new form of linear dichroism.

  • 50. Brandenburg, T
    et al.
    Agåker, Marcus
    Atak, K
    Pflüger, M
    Schwanke, C
    Petit, T
    Lange, K M
    Rubensson, Jan-Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Aziz, E F
    The electronic structure of perfluorodecalin studied by soft X-ray spectroscopy and electronic structure calculations2014In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 42, p. 23379-23385Article in journal (Refereed)
    Abstract [en]

    Fluorine and carbon K absorption and emission spectra of liquid perfluorodecalin are presented and analyzed in terms of density functional calculations-configuration interaction. A comprehensive view of the electronic structure is given, and site-specific intramolecular interactions are investigated in detail. It is found that, while the outer fluorine atoms have excess charge in the ground state, the lowest excitations must be associated with charge transfer towards the inner carbon atoms.

1234567 1 - 50 of 674
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