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  • 201. Kiendl, Benjamin
    et al.
    Levitre, Guillaume
    Hadzifejzovic, Emina
    Lounasvuori, Mailis
    Venerosy, Amelie
    Choudhury, Sneha
    Petit, Tristan
    Aziz, Emad
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Girard, Hugues
    Arnault, Jean-Charles
    Foord, John
    Masson, Geraldine
    Krueger, Anke
    Transition-Metal Functionalized Nanodiamond for Photocatalytic Applications2017Conference paper (Other academic)
  • 202. Kirchgeorg, Robin
    et al.
    Wei, Wei
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lee, Kiyoung
    So, Seugli
    Schmuki, Patrik
    Through-Hole, Self-Ordered Nanoporous Oxide Layers on Titanium, Niobium and Titanium–Niobium Alloys in Aqueous and Organic Nitrate Electrolytes2012In: ChemistryOpen, ISSN 2191-1363, Vol. 1, no 1, p. 21-25Article in journal (Refereed)
  • 203.
    Kizling, Michal
    et al.
    Univ Warsaw, Fac Chem, PL-02093 Warsaw, Poland..
    Draminska, Sylwia
    Univ Warsaw, Fac Chem, PL-02093 Warsaw, Poland..
    Stolarczyk, Krzysztof
    Univ Warsaw, Fac Chem, PL-02093 Warsaw, Poland..
    Tammela, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Wang, Zhaohui
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Bilewicz, Renata
    Univ Warsaw, Fac Chem, PL-02093 Warsaw, Poland..
    Biosupercapacitors for powering oxygen sensing devices2015In: Bioelectrochemistry, ISSN 1567-5394, E-ISSN 1878-562X, Vol. 106, p. 34-40Article in journal (Refereed)
    Abstract [en]

    A biofuel cell comprising electrodes based on supercapacitive materials - carbon nanotubes and nanocellulose/polypyrrole composite was utilized to power an oxygen biosensor. Laccase Trametes versicolor, immobilized on naphthylated multi walled carbon nanotubes, and fructose dehydrogenase, adsorbed on a porous polypyrrole matrix, were used as the cathode and anode bioelectrocatalysts, respectively. The nanomaterials employed as the supports for the enzymes increased the surface area of the electrodes and provide direct contact with the active sites of the enzymes. The anode modified with the conducting polymer layer exhibited significant pseudocapacitive properties providing superior performance also in the high energy mode, e.g., when switching on/off the powered device. Three air-fructose biofuel cells connected in a series converted chemical energy into electrical giving 2 mW power and open circuit potential of 2 V. The biofuel cell system was tested under various externally applied resistances and used as a powering unit for a laboratory designed two-electrode minipotentiostat and a laccase based sensor for oxygen sensing. Best results in terms of long time measurement of oxygen levels were obtained in the pulse mode -45 s for measurement and 15 min for self-recharging of the powering unit.

  • 204. Kizling, Michal
    et al.
    Stolarczyk, Krzysztof
    Kiat, Julianna Sim Sin
    Tammela, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Wang, Zhaohui
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Bilewicz, Renata
    Pseudocapacitive polypyrrole-nanocellulose composite for sugar-air enzymatic fuel cells2015In: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 50, p. 55-59Article in journal (Refereed)
    Abstract [en]

    Efficient, new combination of a bioelectrocatalytic and a pseudocapacitive cellulose-based composite material is reported. The anode comprising Gluconobacter sp. fructose dehydrogenase physically adsorbed on Cladophora sp. Algae nanocellulose/polypyrrole composite provides large catalytic oxidation currents due to large effective surface area of the composite material, and enables storing of the charge. Supercapacitor properties are useful for larger current demands e.g. during switching on-off the devices. Mediatorless catalytic oxidation current densities as high as 14 mA cm(-2) at potentials as negative as -0.17 V vs. Ag/AgCl constitute the best anode performance without using mediators reported to date. The fuel cell with GCE cathode covered with laccase adsorbed on naphthylated multiwalled carbon nanotubes, exhibits improved parameters: open circuit voltage of 0.76 V, and maximum power density 1.6 mW cm(-2).

  • 205.
    Kizling, Michal
    et al.
    Warsaw University.
    Stolarczyk, Krzysztof
    Warsaw University.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Bilewicz, Renata
    Warsaw University.
    Application of cellulose/conductive polymer paper as free standing matrix for enzyme immobilization in enzymatic fuel cell2016Conference paper (Other academic)
  • 206.
    Kizling, Michal
    et al.
    Coll Interfac Individual Studies Math & Nat Sci M, Stefana Banacha 2C, PL-02097 Warsaw, Poland..
    Stolarczyk, Krzysztof
    Univ Warsaw, Dept Chem, Pasteura 1, PL-02093 Warsaw, Poland..
    Tammela, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Wang, Zhaohui
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nyholm, Leif
    Golimowski, Jerzy
    Univ Warsaw, Dept Chem, Pasteura 1, PL-02093 Warsaw, Poland..
    Bilewicz, Renata
    Univ Warsaw, Dept Chem, Pasteura 1, PL-02093 Warsaw, Poland..
    Bioelectrodes based on pseudocapacitive cellulose/polypyrrole composite improve performance of biofuel cell2016In: Bioelectrochemistry, ISSN 1567-5394, E-ISSN 1878-562X, Vol. 112, p. 184-190Article in journal (Refereed)
    Abstract [en]

    Enzymatic electrodes with high internal capacitance, based on cellulose/polypyrrole composite were optimized and utilized to design improved enzymatic fuel cell. Fructose dehydrogenase Gluconobacter sp. specifically adsorbed on the cellulose/polypyrrole matrix and electrophoretically immobilized and electrochemically entrapped Laccase Trametes versicolor, were used as the anode and cathode bioelectrocatalysts, respectively. The cellulose/polypyrrole composite film exhibited pseudocapacitive properties under mild pH conditions. Following modification with carboxylic groups the composite material enabled highly efficient adsorption of enzyme and provided good electrical contact between the enzymatic active sites and the electrode surface. The modified cellulose/polypyrrole composite based electrode was used for the anode leading to mediatorless fructose oxidation giving large catalytic current density, 12.8 mA cm(-2). Laccase and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as the mediator entrapped in the cellulose/polypyrrole composite film generated dioxygen reduction current density of 2 mA cm(-2). Application of pseudocapacitive matrix and decreasing the distance between electrodes to 1 mm lead to improvement of the biofuel cell power output and its regeneration ability. The power of the cell was found to increase by introduction of a preconditioning step during which the cell was kept at open circuit voltage under fuel flow. After 24 h of preconditioning the matrix was recharged and the device output reached the power, 2.1 mW cm(-2) and OCV, 0.59 V.

  • 207.
    Kjellander, Marcus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Billinger, Erika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Ramachandraiah, Harisha
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Bergström Lind, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Johansson, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    A flow-through nanoporous alumina trypsin bioreactor for mass spectrometry peptide fingerprinting2018In: Journal of Proteomics, ISSN 1874-3919, E-ISSN 1876-7737, Vol. 172, p. 165-172Article in journal (Refereed)
    Abstract [en]

    Mass spectrometry-based proteomics benefits from efficient digestion of protein samples. In this study, trypsinwas immobilized on nanoporous anodized alumina membranes to create an enzyme reactor suitable for peptidemassfingerprinting. The membranes were derivatized with 3-aminopropyltriethoxysilane and the amino groupswere activated with carbonyldiimidazole to allow coupling of porcine trypsin viaε-amino groups. The functionwas assessed using the artificial substrate Nα-Benzoyl-L-arginine 4-nitroanilide hydrochloride, bovine ribonu-clease A and a human plasma sample. A 10-membraneflow-through reactor was used for fragmentation and MSanalysis after a single pass of substrate both by collection of product and subsequent off-line analysis, and bycoupling on-line to the instrument. The peptide pattern allowed correct identification of the single target proteinin both cases, and of > 70 plasma proteins in single pass mode followed by LC-MS analysis. The reactor retained76% of the initial activity after 14 days of storage and repeated use at room temperature.

    Significance:This manuscript describes the design of a stable enzyme reactor that allows efficient and fast di-gestion with negligible leakage of enzyme and enzyme fragments. The high stability facilitates the use in anonline-setup with MS detection since it allows the processing of multiple samples within an extended period of time without replacement.

  • 208.
    Kjellander, Marcus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Gotz, Kathrin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Liljeruhm, Josefine
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Johansson, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Steady-state generation of hydrogen peroxide: kinetics and stability of alcohol oxidase immobilized on nanoporous alumina2013In: Biotechnology letters, ISSN 0141-5492, E-ISSN 1573-6776, Vol. 35, no 4, p. 585-590Article in journal (Refereed)
    Abstract [en]

    Alcohol oxidase from Pichia pastoris was immobilized on nanoporous aluminium oxide membranes by silanization and activation by carbonyldiimidazole to create a flow-through enzyme reactor. Kinetic analysis of the hydrogen peroxide generation was carried out for a number of alcohols using a subsequent reaction with horseradish peroxidase and ABTS. The activity data for the immobilized enzyme showed a general similarity with literature data in solution, and the reactor could generate 80 mmol H2O2/h per litre reactor volume. Horseradish peroxidase was immobilized by the same technique to construct bienzymatic modular reactors. These were used in both single pass mode and circulating mode. Pulsed injections of methanol resulted in a linear relation between response and concentration, allowing quantitative concentration measurement. The immobilized alcohol oxidase retained 58 % of initial activity after 3 weeks of storage and repeated use.

  • 209.
    Kjellander, Marcus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Mazari, Aslam M.A.
    Department of Neurochemistry, Stockholm University, SE-10691, Sweden.
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Mannervik, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Johansson, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Glutathione transferases immobilized on nanoporous alumina: Flow system kinetics, screening and stability2014In: Analytical Biochemistry, ISSN 0003-2697, E-ISSN 1096-0309, Vol. 446, p. 59-63Article in journal (Refereed)
    Abstract [en]

    The previously uncharacterized Drosophila melanogaster Epsilon class glutathione transferases E6 and E7 were immobilized on nanoporous alumina. The nanoporous anodized alumina membranes were derivatized with 3-aminopropyl-triethoxysilane and the amino groups were activated with carbonyldiimidazole to allow coupling of the enzymes via ∊-amino groups. Kinetic analyses of the immobilized enzymes were carried out in a circulating flow system using CDNB (1-chloro-2,4-dinitrobenzene) as substrate, followed by specificity screening with alternative substrates. A good correlation was observed between the substrate screening data for immobilized enzyme and corresponding data for the enzyme in solution. A limited kinetic study was also carried out on immobilized human GST S1-1 (also known as hematopoietic prostaglandin D synthase). The stability of the immobilized enzymes was virtually identical to that for enzymes in solution and no leakage of enzyme from the matrix could be observed.

  • 210.
    Knut, Ronny
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Lagerqvist, Ulrika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Palmgren, Pål
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Pal, P.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Pohl, Annika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Karis, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Photoinduced reduction of surface states in Fe:ZnO2015In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 142, no 20, article id 204703Article in journal (Refereed)
    Abstract [en]

    We report on the electronic structure of nano-crystalline Fe:ZnO, which has recently been found to be an efficient photocatalyst. Using resonant photoemission spectroscopy, we determine the binding energy of Fe 3d states corresponding to different valencies and coordination of the Fe atoms. The photo-activity of ZnO reduces Fe from 3+ to 2+ in the surface region of the nano-crystalline material due to the formation of oxygen vacancies. Electronic states corresponding to low-spin Fe2+ are observed and attributed to crystal field modification at the surface. These states are potentially important for the photocatalytic sensitivity to visible light due to their location deep in the ZnO bandgap. X-ray absorption and x-ray photoemission spectroscopy suggest that Fe is only homogeneously distributed for concentrations up to 3%. Increased concentrations does not result in a higher concentration of Fe ions in the surface region. This is limiting the photocatalytic functionality of ZnO, where the most efficient Fe doping concentration has been shown to be 1%-4%.

  • 211.
    Kontos, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Fang, Hailiang
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Li, Jiheng
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Delczeg-Czirjak, Erna Krisztina
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Shafeie, Samrand
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Gunnarsson, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Measured and calculated properties of B-doped τ-phase MnAl: A rare earth free permanent magnet2019In: Journal of Magnetism and Magnetic Materials, Vol. 474, p. 591-598Article in journal (Refereed)
    Abstract [en]

    The metastable tetragonal τ-phase MnAl has been doped interstitially with B through a drop synthesis method creating the (Mn0.55Al0.45)B0.02 compound. The as-casted samples were annealed, quenched and thereafter ball-milled and relaxed in order to decrease grain size and reduce the number of crystallographic defects. The Curie temperature of the quenched sample was estimated to 655 K. The magnetization, coercivity and anisotropy were analyzed with respect to flash-milling time, relaxation time and temperature. The results show that (Mn0.55Al0.45)B0.02 could be directly obtained from drop synthesis. The highest measured saturation magnetization of 393 kA/m (measured at ±1440kA/m) was achieved with a relaxation process after 1.5h milling, giving a theoretical maximum energy product of 48 kJ/m3. The highest value of the coercivity was 355 kA/m achieved by flash-milling for 10 h. However, the high coercivity was achieved at an expense of low saturation magnetization.

  • 212. Korablov, Dmytro
    et al.
    Ångstrom, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Ley, Morten B.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Besenbacher, Flemming
    Jensen, Torben R.
    Activation effects during hydrogen release and uptake of MgH22014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 18, p. 9888-9892Article in journal (Refereed)
    Abstract [en]

    Scandium(II)hydride, ScH2, and scandium(III)chloride, ScCl3, are explored as additives to facilitate hydrogen release and uptake for magnesium hydride. These additives are expected to form more homogeneous composites with Mg/MgH2 as compared to metallic scandium. However, scandium(III)chloride, reacts with MgH2 during mechano-chemical treatment and form ScH2 and MgCl2 (that later crystallise during heat treatment). The composite MgH2-ScH2 was investigated using in-situ synchrotron radiation powder X-ray diffraction during up to five cycles of continuous release and uptake of hydrogen at isothermal conditions at 320, 400 and 450 degrees C and p(H-2) = 100-150 or 10(-2) bar. The data were analysed by Rietveld refinement and no reaction is observed between either MgH2/ScH2 or Mg/ScH2 during cycling. The extracted sigmoidal shaped curves for formation or decomposition of Mg/MgH2 suggest that a nucleation process is preceding the crystal growth. The reaction rate increases with increasing number of cycles of hydrogen release and uptake at isothermal conditions possibly due to activation effects. This kinetic enhancement is strongest between the first cycles and may be denoted an activation effect. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  • 213.
    Koroleva, A. F.
    et al.
    Moscow Technol Univ, Moscow Inst Radio Engn Elect & Automat, Moscow, Russia.
    Bush, A. A.
    Moscow Technol Univ, Moscow Inst Radio Engn Elect & Automat, Moscow, Russia.
    Kamentsev, K. E.
    Moscow Technol Univ, Moscow Inst Radio Engn Elect & Automat, Moscow, Russia.
    Shkuratov, V. Ya.
    Moscow Technol Univ, Moscow Inst Radio Engn Elect & Automat, Moscow, Russia.
    Ivanov, Sergey
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics. Russian State Sci Ctr, Karpov Inst Phys Chem, Moscow, Russia.
    Cherepanov, V. M.
    Natl Res Ctr, Kurchatov Inst, Moscow, Russia.
    Shafeie, Samrand
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Synthesis, X-ray Diffraction Characterization, Mössbauer Spectroscopy, and Dielectric Properties of Solid Solutions in the PbFe2/3W1/3O3–PbSc2/3W1/3O3 System2018In: Inorganic Materials (Neorganicheskie materialy), ISSN 0020-1685, E-ISSN 1608-3172, Vol. 54, no 3, p. 288-294Article in journal (Refereed)
    Abstract [en]

    Ceramic Pb(Fe1–xSc x )2/3W1/3O3 samples with 0 ≤ x ≤ 1 have been prepared and characterized by X-ray diffraction, Mössbauer spectroscopy, and dielectric and pyroelectric measurements. The stoichiometry ranges of the perovskite solid solutions in this system have been identified, their structural parameters have been determined, and their dielectric permittivity, dielectric loss tangent, resistivity, and thermally stimulated depolarization current have been measured as functions of temperature. The composition dependences of the dielectric properties for the solid solutions have been obtained. The solid solutions have been shown to exhibit ferroelectric relaxor properties, with a well-defined maximum in their permittivity in the range 180–250 K.

  • 214. Kritikos, Mikael
    et al.
    Moustiakimov, Marat
    Westin, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Synthesis, structure and properties of two unexpected square pyramidal pentanuclear oxo-isopropoxide molecules: Ce5O(OPri)13 and La5O(OPri)13(HOPri)22012In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 384, p. 125-132Article in journal (Refereed)
    Abstract [en]

    The synthesis, structure and properties of two pentanuclear oxo-alkoxides are described. A combination of metathesis of LnCl(3) and 3KOPr(i) and stoichiometric hydrolysis resulted in the solvated oxo-alkoxide La5O(OPri)(13)(HOPri)(2) (1) and the non-solvated Ce5O(OPri)(13) (3). 1 is rather stable at room-temperature, but desolvation into La5O(OPri)(13) (2), identified by spectroscopy, could be achieved by vacuum treatment. 1 and 3 were structurally characterised by single-crystal X-ray diffraction. In both 1 and 3 the metal atoms have a square pyramidal arrangement. In 1, each crystallographically independent La5O(OPri)(13) (HOPri)(2) molecule contains 3 six-coordinated and 2 seven-coordinated La atoms, while in 3 all Ce atoms are six-coordinated. 3 Is the first structurally characterized example of a purely Ce3+ isopropoxide. Characterisations of 1 and 3 were by IR- and Raman spectroscopy and differential scanning calorimetry, and for 1 also by H-1 and C-13 NMR spectroscopy. The great similarity of the IR spectra of the solid 1 and 3, respectively, to their corresponding solutions, showed that the molecular structure present in the solid state is close to retained in solution.

  • 215. Kronawitter, C. X.
    et al.
    Zegkinoglou, I.
    Shen, S. -H
    Liao, P.
    Cho, I. S.
    Zandi, O.
    Liu, Y. -S
    Lashgari, Koroush
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Westin, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Guo, J. -H
    Himpsel, F. J.
    Carter, E. A.
    Zheng, X. L.
    Hamann, T. W.
    Koel, B. E.
    Mao, S. S.
    Vayssieres, L.
    Titanium incorporation into hematite photoelectrodes: theoretical considerations and experimental observations2014In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 7, no 10, p. 3100-3121Article in journal (Refereed)
    Abstract [en]

    A theoretical and experimental perspective on the role of titanium impurities in hematite (alpha-Fe2O3) nanostructured photoelectrodes for solar fuel synthesis devices is provided. Titanium incorporation is a known correlate to efficiency enhancement in alpha-Fe2O3 cc photoanodes for solar water oxidation; here the relevant literature and the latest advances are presented and various proposed mechanisms for enhancement are contrasted. Available experimental evidence suggests that Ti incorporation increases net electron carrier concentrations in electrodes, most likely to the extent that (synthesis-dependent) charge compensating cation vacancies are not present. However, electron conductivity increases alone cannot quantitatively account for the large associated photoelectrochemical performance enhancements. The magnitudes of the effects of Ti incorporation on electronic and magnetic properties appear to be highly synthesis-dependent, which has made difficult the development of consistent and general mechanisms explaining experimental and theoretical observations. In this context, we consider how the electronic structure correlates with Ti impurity incorporation in alpha-Fe2O3 a from the perspective of synchrotron-based soft X-ray absorption spectroscopy measurements. Measurements are performed on sets of electrodes fabricated by five relevant and unrelated chemical and physical techniques. The effects of titanium impurities are reflected in the electronic structure through several universally observed spectral characteristics, irrespective of the synthesis techniques. Absorption spectra at the oxygen K-edge show that Ti incorporation is associated with new oxygen 2p-hybridized states, overlapping with and distorting the known unoccupied Fe 3d-O 2xp band of alpha-Fe2O3. This is an indication of mixing of Ti s and d states in the conduction band of alpha-Fe2O3. cc A comparison of spectra obtained with electron and photon detection shows that the effects of Ti incorporation on the conduction band are more pronounced in the near-surface region. Titanium L-2,L-3-edge absorption spectra show that titanium is incorporated into alpha-Fe2O3 as Ti4+ by all fabrication methods, with no long-range titania order detected. Iron L-2,L-3-edge absorption spectra indicate that Ti incorporation is not associated with the formation, of any significant concentrations of Fe2+, an observation common to many prior studies on this material system.

  • 216.
    Kryshtal, O.
    et al.
    AGH Univ Sci & Technol, Int Ctr Electron Microscopy Mat Sci, Comp Sci, Al Mickiewicza 30, PL-30059 Krakow, Poland;AGH Univ Sci & Technol, Fac Met Engn & Ind, Comp Sci, Al Mickiewicza 30, PL-30059 Krakow, Poland.
    Kruk, A.
    AGH Univ Sci & Technol, Int Ctr Electron Microscopy Mat Sci, Comp Sci, Al Mickiewicza 30, PL-30059 Krakow, Poland;AGH Univ Sci & Technol, Fac Met Engn & Ind, Comp Sci, Al Mickiewicza 30, PL-30059 Krakow, Poland.
    Mao, Fang
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Taher, Mamoun
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Corp Res, Insulat & Mat Technol, Abb Ab, Vasteras, Sweden.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Czyrska-Filemonowicz, A.
    AGH Univ Sci & Technol, Int Ctr Electron Microscopy Mat Sci, Comp Sci, Al Mickiewicza 30, PL-30059 Krakow, Poland;AGH Univ Sci & Technol, Fac Met Engn & Ind, Comp Sci, Al Mickiewicza 30, PL-30059 Krakow, Poland.
    Microstructure and phase composition of the Ag-Al film wear track: Through-thickness characterization by advanced electron microscopy2019In: Archives of Metallurgy and Materials, ISSN 1733-3490, E-ISSN 2300-1909, Vol. 64, no 1, p. 251-256Article in journal (Refereed)
    Abstract [en]

    Analytical transmission electron microscopy has been applied to characterize the microstructure, phase and chemical composition of the Ag-Al wear track throughout its thickness down to the atomic level. Microscopy findings have been correlated with Ag-Al film tribological properties to understand the effect of the hexagonal solid solution phase on the tribological properties of this film. Ag-25Al (at.%) films have been produced by simultaneous magnetron sputtering of components in Ar atmosphere under 1 mTorr pressure and subjected to pin-on-disc tribological tests. It has been shown that hcp phase with (001) planes aligned parallel to the film surface dominates both in as-deposited and in tribofilm areas of the Ag-Al alloy film. Possible mechanisms of reduced friction in easily oxidized Ag-Al system are discussed and the mechanism based on readily shearing basal planes of the hcp phase is considered as the most probable one.

  • 217.
    Kuball, Alexander
    et al.
    Saarland Univ, Chair Metall Mat, Campus C6-3, D-66123 Saarbrucken, Germany.
    Bochtler, Benedikt
    Saarland Univ, Chair Metall Mat, Campus C6-3, D-66123 Saarbrucken, Germany.
    Gross, Oliver
    Saarland Univ, Chair Metall Mat, Campus C6-3, D-66123 Saarbrucken, Germany.
    Pacheco, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Saarland Univ, Chair Metall Mat, Campus C6-3, D-66123 Saarbrucken, Germany.
    Stolpe, Moritz
    Saarland Univ, Chair Metall Mat, Campus C6-3, D-66123 Saarbrucken, Germany;Heraeus Deutschland GmbH & Co KG, Heraeusstr 12-14, D-63450 Hanau, Germany.
    Hechler, Simon
    Saarland Univ, Chair Metall Mat, Campus C6-3, D-66123 Saarbrucken, Germany.
    Busch, Ralf
    Saarland Univ, Chair Metall Mat, Campus C6-3, D-66123 Saarbrucken, Germany.
    On the bulk glass formation in the ternary Pd-Ni-S system2018In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 158, p. 13-22Article in journal (Refereed)
    Abstract [en]

    We report on the formation of bulk metallic glasses in the ternary Pd-Ni-S system. In a large compositional range, glass formation is observed by copper mold casting with a glass forming ability of up to 2 mm in diameter for the composition Pd37Ni37S26. The best compromise of thermal stability upon heating from the as-cast state and glass forming ability was found for Pd31Ni42S27, having a critical diameter of 1.5 mm and an extension of the supercooled liquid region of 27.2 K (Delta T-x = T-x - T-g). Differential scanning calorimetry and X-ray diffraction experiments were conducted in order to study the influence of the composition on the glass forming ability and thermal stability. The primary precipitating crystalline phases Ni3S2 and Pd4S are identified by in-situ high energy synchrotron X-ray scattering experiments upon heating from the glassy state as well as upon cooling from the equilibrium liquid. Finally, the origin of the bulk glass formation in this novel system is discussed regarding thermodynamics and kinetics and compared to current models for the prediction of the glass forming ability. Furthermore, the mechanical properties are investigated and discussed with respect to the rather fragile kinetic behavior. All in all, we gain new insights into the process of glass formation in this novel alloying system and give conclusions about the determining contributions for the glass forming ability and glass forming range.

  • 218.
    Kumar, Ankit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Wetterskog, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tai, Cheuk-Wai
    Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden.
    Akansel, Serkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Husain, Sajid
    Department of Physics, Indian Institute of Technology Delhi, New Delhi, India.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Brucas, Rimantas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Chaudhary, Sujeet
    Department of Physics, Indian Institute of Technology Delhi, New Delhi, India.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Effect of in situ electric-field-assisted growth on antiphase boundaries in epitaxial Fe3O4 thin films on MgO2018In: Physical Review Materials, ISSN 2475-9953, Vol. 2, no 5, article id 054407Article in journal (Refereed)
    Abstract [en]

    Antiphase boundaries (APBs) normally form as a consequence of the initial growth conditions in all spinel ferrite thin films. These boundaries result from the intrinsic nucleation and growth mechanism, and are observed as regions where the periodicity of the crystalline lattice is disrupted. The presence of APBs in epitaxial films of the inverse spinel Fe3O4 alters their electronic and magnetic properties due to strong antiferromagnetic (AF) interactions across these boundaries. We explore the effect of using in-plane in situ electric-field-assisted growth on the formation of APBs in heteroepitaxial Fe3O4(100)/MgO(100) thin films. The electric-field-assisted growth is found to reduce the AF interactions across APBs and, as a consequence, APB-free thin-film-like properties are obtained, which have been probed by electronic, magnetic, and structural characterization. The electric field plays a critical role in controlling the density of APBs during the nucleation process by providing an electrostatic force acting on adatoms and therefore changing their kinetics. This innovative technique can be employed to grow epitaxial spinel thin films with controlled AF interactions across APBs.

  • 219.
    Kádas, Krisztina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Iusan, Diana
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Hellsvik, J.
    Royal Inst Technol KTH, Sch Informat & Commun Technol, Dept Mat & Nanophys, Elect 229, S-16440 Kista, Sweden..
    Cedervall, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Berastegui, Pedro
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Eriksson, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    AlM2B2 (M =Cr, Mn, Fe, Co, Ni): a group of nanolaminated materials2017In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 29, no 15, article id 155402Article in journal (Refereed)
    Abstract [en]

    Combining theory with experiments, we study the phase stability, elastic properties, electronic structure and hardness of layered ternary borides AlCr2B2, AlMn2B2, AlFe2B2, AlCo2B2, and AlNi2B2. We find that the first three borides of this series are stable phases, while AlCo2B2 and AlNi2B2 are metastable. We show that the elasticity increases in the boride series, and predict that AlCr2B2, AlMn2B2, and AlFe2B2 are more brittle, while AlCo2B2 and AlNi2B2 are more ductile. We propose that the elasticity of AlFe2B2 can be improved by alloying it with cobalt or nickel, or a combination of them. We present evidence that these ternary borides represent nanolaminated systems. Based on SEM measurements, we demonstrate that they exhibit the delamination phenomena, which leads to a reduced hardness compared to transition metal mono-and diborides. We discuss the background of delamination by analyzing chemical bonding and theoretical work of separation in these borides.

  • 220.
    Kádas, Krisztina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Sundberg, Jill
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Eriksson, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Formation of 2D transition metal dichalcogenides on TiC1-xAx surfaces (A=S, Se, Te): A theoretical study2014In: Journal of Materials Research, ISSN 0884-2914, E-ISSN 2044-5326, Vol. 29, no 2, p. 207-214Article in journal (Refereed)
    Abstract [en]

    Using first principle density functional calculations, we study the formation of 2D transition metaldichalcogenides (TMDs) on TiC1-xAx, (A = S, Se, and Te) surfaces. We examine the structural misfits between chalcogen-containing TiC and different TMDs and demonstrate that the conditions for formation of TMDs are fulfilled in TiC1-xAx. We also demonstrate the influence of chalcogens on the cohesive properties and electronic structure of the carbides. We find that they react with W and form W-dichalcogenides. In the experimentally reported Ti–C–S nanocomposite coatings, the carbide grains are embedded in an amorphous carbon matrix. We discuss here the role ofthis matrix in the reaction. We propose that TiC1-xTex and TiC1-xSex are the favorable sources fordichalcogenide formation and suggest an alternative way to produce 2D materials in general. Furthermore, we argue that using Ti–C–Te or Ti–C–Se in nanocomposite coatings may be more advantageous for tribological applications than that of Ti–C–S.

  • 221.
    Lagerqvist, Ulrika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Solution-Chemical Synthesis of Cobalt and Iron:Zinc Oxide Nanocomposite Films2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The potentially most important challenges today are related to energy and the environment. New materials and methods are needed in order to, in a sustainable way, convert and store energy, reduce pollution, and clean the air and water from contaminations. In this, nanomaterials and nanocomposites play a key role, and hence knowledge about the relation between synthesis, structure, and properties of nanosystems is paramount.

    This thesis demonstrates that solution-chemical synthesis, using amine-modified acetates and nitrates, can be used to prepare widely different nanostructured films. By adjusting the synthesis parameters, metals, oxides, and metal–oxide or oxide–oxide nanocomposites were prepared for two systems based on Co and Zn:Fe, respectively, and the films were characterised using diffraction, spectroscopy, and microscopy techniques, and SQUID magnetometry.

    A variety of crystalline cobalt films—Co metal, CoO, Co3O4, and composites with different metal:oxide ratios—were synthesised. Heat-treatment parameters and control of the film thickness enabled tuning of the phase ratios. Random and layered Co–CoO composites were prepared by utilising different heating rates and gas flow rates together with a morphology effect associated with the furnace tube. The Co–CoO films exhibited exchange bias due to the ferromagnetic–antiferromagnetic interaction between the Co and CoO, whereas variations in e.g. coercivity and exchange bias field were attributed to differences in the structure and phase distribution.

    Ordered structures of wurtzite ZnO surrounded by amorphous ZnxFeyO were prepared through controlled phase segregation during the heating, which after multiple coating and heating cycles yielded ZnO–ZnxFeyO superlattices. The amorphous ZnxFeyO was a prerequisite for superlattice formation, and it profoundly affected the ZnO phase, inhibiting grain growth and texture, already from 1% Fe. In addition, ZnO–ZnxFeyO exhibited a photocatalytic activity for the oxidation of water that was higher than results reported for pure ZnO, and comparable to recent results reported for graphene-modified ZnO.

    List of papers
    1. Synthesis and characterization of cobalt oxide and composite thin films
    Open this publication in new window or tab >>Synthesis and characterization of cobalt oxide and composite thin films
    2014 (English)In: Advances in Materials, ISSN 2327-2503, Vol. 3, no 5, p. 52-57Article in journal (Refereed) Published
    Abstract [en]

    Cobalt oxide and composite thin films were synthesized by spin-coating technique, followed by heating to 500°C in oxidizing, inert, or reducing atmospheres. Methanolic solutions of triethanolamine complexes of cobalt acetates and nitrates were spin-coated at 1000, 2000, and 3000 rpm. The influence of heating parameters and film thickness on the phase content of the films were investigated, using grazing incidence X-ray diffraction, X-ray reflectivity, and scanning electron microscopy. By tuning the synthesis parameters, Co3O4, CoO and Co films were obtained, as well as CoO-Co and Co3O4-CoO composite films of varying phase ratios.

    Place, publisher, year, edition, pages
    Science Publishing Group, 2014
    Keywords
    Cobalt Oxides, CoO-Co Composites, Solution Synthesis, Thin Films, Tailor Composition
    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-280377 (URN)10.11648/j.am.20140305.14 (DOI)
    Available from: 2016-03-09 Created: 2016-03-09 Last updated: 2016-06-01
    2. Morphology effects on exchange anisotropy in Co-CoO nanocomposite films
    Open this publication in new window or tab >>Morphology effects on exchange anisotropy in Co-CoO nanocomposite films
    Show others...
    2015 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 576, p. 11-18Article in journal (Refereed) Published
    Abstract [en]

    Co-CoO composite films were prepared by solution chemical technique using amine-modified nitrates and acetates in methanol. We study how particle size and porosity can be tuned through the synthesis parameters and how this influences the magnetic properties. Phase content and microstructure were characterised with grazing incidence X-ray diffraction and electron microscopy, and the magnetic properties were studied by magnetometry and magnetic force microscopy. Composite films were obtained by heating spin-coated films in Ar followed by oxidation in air at room temperature, and the porosity and particle size of the films were controlled by gas flow and heating rate. The synthesis yielded dense films with a random distribution of metal and oxide nanoparticles, and layered films with porosity and sintered primary particles. Exchange anisotropy, revealed as a shift towards negative fields of the magnetic hysteresis curve, was found in all films. The films with a random distribution of metal and oxide nanoparticles displayed a significantly larger coercivity and exchange anisotropy field compared to the films with a layered structure, whereas the layered films displayed a larger nominal saturation magnetisation. The magnitude of the coercivity decreased with increasing Co grain size, whereas increased porosity caused an increased tilt of the magnetic hysteresis curve. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license

    Keywords
    Co-CoO composite, Thin film, Solution chemical synthesis, Morphology effect, Magnetism, Exchange anisotropy, Magnetic stray field
    National Category
    Physical Sciences Engineering and Technology
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-246807 (URN)10.1016/j.tsf.2014.11.064 (DOI)000349373300002 ()
    Available from: 2015-03-16 Created: 2015-03-10 Last updated: 2017-12-04Bibliographically approved
    3. ZnO-ZnxFeyO Superlattices - Influence of Metastable Phases on Structure and Properties in Fe:Zn:O
    Open this publication in new window or tab >>ZnO-ZnxFeyO Superlattices - Influence of Metastable Phases on Structure and Properties in Fe:Zn:O
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-280379 (URN)
    Available from: 2016-03-11 Created: 2016-03-09 Last updated: 2016-06-01
    4. Photoinduced reduction of surface states in Fe:ZnO
    Open this publication in new window or tab >>Photoinduced reduction of surface states in Fe:ZnO
    Show others...
    2015 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 142, no 20, article id 204703Article in journal (Refereed) Published
    Abstract [en]

    We report on the electronic structure of nano-crystalline Fe:ZnO, which has recently been found to be an efficient photocatalyst. Using resonant photoemission spectroscopy, we determine the binding energy of Fe 3d states corresponding to different valencies and coordination of the Fe atoms. The photo-activity of ZnO reduces Fe from 3+ to 2+ in the surface region of the nano-crystalline material due to the formation of oxygen vacancies. Electronic states corresponding to low-spin Fe2+ are observed and attributed to crystal field modification at the surface. These states are potentially important for the photocatalytic sensitivity to visible light due to their location deep in the ZnO bandgap. X-ray absorption and x-ray photoemission spectroscopy suggest that Fe is only homogeneously distributed for concentrations up to 3%. Increased concentrations does not result in a higher concentration of Fe ions in the surface region. This is limiting the photocatalytic functionality of ZnO, where the most efficient Fe doping concentration has been shown to be 1%-4%.

    National Category
    Physical Sciences Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-258046 (URN)10.1063/1.4921570 (DOI)000355919300030 ()26026457 (PubMedID)
    Available from: 2015-07-13 Created: 2015-07-10 Last updated: 2017-12-04
    5. Optical and Photocatalytic Properties of Zinc Oxide and Iron-Zinc Oxide Heterojunctions
    Open this publication in new window or tab >>Optical and Photocatalytic Properties of Zinc Oxide and Iron-Zinc Oxide Heterojunctions
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-280378 (URN)
    Available from: 2016-03-11 Created: 2016-03-09 Last updated: 2016-06-01
  • 222.
    Lagerqvist, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jacobsson, T.Jesper
    Laboratory for Photomolecular Science, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015-Lausanne, Switzerland.
    Ottosson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Pohl, Annika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Optical and Photocatalytic Properties of Zinc Oxide and Iron-Zinc Oxide HeterojunctionsManuscript (preprint) (Other academic)
  • 223.
    Lagerqvist, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Knut, Ronny
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Ottosson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Hoffmann, Andrea
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Wan, Wei
    Department of Materials and Environmental Chemistry, Stockholm University.
    Karis, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Pohl, Annika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Department of Materials and Environmental Chemistry, Stockholm University.
    ZnO-ZnxFeyO Superlattices - Influence of Metastable Phases on Structure and Properties in Fe:Zn:OManuscript (preprint) (Other academic)
  • 224.
    Lagerqvist, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Gunnarsson, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Lu, Jun
    Hultman, Lars
    Ottosson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Pohl, Annika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Morphology effects on exchange anisotropy in Co-CoO nanocomposite films2015In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 576, p. 11-18Article in journal (Refereed)
    Abstract [en]

    Co-CoO composite films were prepared by solution chemical technique using amine-modified nitrates and acetates in methanol. We study how particle size and porosity can be tuned through the synthesis parameters and how this influences the magnetic properties. Phase content and microstructure were characterised with grazing incidence X-ray diffraction and electron microscopy, and the magnetic properties were studied by magnetometry and magnetic force microscopy. Composite films were obtained by heating spin-coated films in Ar followed by oxidation in air at room temperature, and the porosity and particle size of the films were controlled by gas flow and heating rate. The synthesis yielded dense films with a random distribution of metal and oxide nanoparticles, and layered films with porosity and sintered primary particles. Exchange anisotropy, revealed as a shift towards negative fields of the magnetic hysteresis curve, was found in all films. The films with a random distribution of metal and oxide nanoparticles displayed a significantly larger coercivity and exchange anisotropy field compared to the films with a layered structure, whereas the layered films displayed a larger nominal saturation magnetisation. The magnitude of the coercivity decreased with increasing Co grain size, whereas increased porosity caused an increased tilt of the magnetic hysteresis curve. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license

  • 225.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    A theoretical approach to the energetic stability and geometry of hydrogen and oxygen terminated diamond (100) surfaces2009Conference paper (Refereed)
  • 226.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Effect of diamond surface modification by biomolecular adhesion –: a quantum mechanical study2019In: Novel Aspects of Diamond: from growth to applications / [ed] Nianjun Yang, Springer, 2019Chapter in book (Refereed)
  • 227.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Effect of Substitutional or Chemisorbed Nitrogen on the Diamond (100) Growth Process2009Conference paper (Refereed)
  • 228.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Surface Chemistry of Diamond2015In: Novel Aspects Of Diamond: From Growth To Applications, Springer Berlin/Heidelberg, 2015, p. 53-83Chapter in book (Refereed)
    Abstract [en]

    The diamond material possesses very attractive properties, such as superior electronic properties (when doped), in addition to a controllable surface termination. During the process of diamond synthesis, the resulting chemical properties will mainly depend on the adsorbed species. These species will have the ability to influence both the chemical and electronic properties of diamond. All resulting (and interesting) properties of a terminated diamond surface, make it clear that surface termination is very important for especially those applications in which diamond can function as an electrode material. Theoretical modeling has during the last decades been proven to become highly valuable in the explanation and prediction of experimental results. Simulation of the dependence of various factors influencing the surface reactivity, will aid important information about surface processes including surface stability, modification and functionalization. Other examples include thin film growth mechanisms and surface electrochemistry.

  • 229.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Surface Modification of Diamond for Chemical Sensor Applications: simulations and Modeling2012In: Chemical Sensors: Simulation and Modeling, New York: Momentum Press , 2012Chapter in book (Refereed)
  • 230.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Surface properties of diamond under atmospheric conditions: A quantum mechanical approach.2005In: New Diamond and Frontier Carbon Technologies, Springer, 2005Chapter in book (Refereed)
  • 231.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    The Effect of Dopants on Diamond Surface Properties and Growth2017Book (Other academic)
  • 232.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Partial Electron Transfer during Vapor Growth of Diamond on a (111) Surface1999In: Journal of Physical Chemistry, Vol. 103, p. 2735-Article in journal (Refereed)
  • 233.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    An Ab Initio Study of the Nucleation of Diamond on the Edges of the Graphitic (111) Plane1994In: Journal of Physical Chemistry, p. 5019-Article in journal (Refereed)
  • 234.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Nearest-Neighbour Influence on Hydrocarbon Adsorption on Diamond (111): Studied by Ab Initio Calculations1995In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, p. 10003-Article in journal (Refereed)
  • 235.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Adsorption of Halogen-Containing Methane on Diamond1998In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, p. 1138-Article in journal (Refereed)
  • 236.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Stability of Hydrogen Terminated Diamond (111) Surfaces1997In: Journal of Physical Chemistry, p. 76-Article in journal (Refereed)
  • 237.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Ab Initio Study of Hydrocarbons on Diamond (111)1993In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 2, p. 949-Article in journal (Refereed)
  • 238.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lunell, Sten
    Carlsson, Jan-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Adsorption of hydrocarbons on a Diamond (111) Surface: An Ab Initio Quantum Mechanical Study1993In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, no 4, p. 2666-Article in journal (Refereed)
  • 239.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Stutzmann, Martin
    Hetzl, Martin
    Polarity Control of GaN Nanowires on Diamond:: Experiment and Theory2018Conference paper (Other academic)
  • 240.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tegenfeldt, Jörgen
    A Nuclear Magnetic Resonance Study of the Mobility of Water Molecules in NaHC2O4 H2O1988In: Journal of Molecular Structure, ISSN 0022-2860, E-ISSN 1872-8014, Vol. 178, p. 315-Article in journal (Refereed)
  • 241.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tegenfeldt, Jörgen
    A Nuclear Magnetic Resonance Study of the Molecular Mobility in Ba(NO2)2H2O1987In: Acta Chemica Scandinavica, ISSN 0904-213X, E-ISSN 1902-3103, Vol. A41, p. 59-Article in journal (Refereed)
  • 242.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tegenfeldt, Jörgen
    A Nuclear Magnetic Resonance Study of the Motion of Water Moleules and LIthium Ions in Pyroelectric Lithium Perchlorate Trihydrate1985In: Journal of Magnetic Resonance, Vol. 64, p. 451-Article in journal (Refereed)
  • 243.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tegenfeldt, Jörgen
    An NMR Study of the Moelcular Mobility in BeSO4 4H2O1988In: Journal of Molecular Structure, ISSN 0022-2860, E-ISSN 1872-8014, Vol. 176, p. 303-Article in journal (Refereed)
  • 244.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tegenfeldt, Jörgen
    Kvick, Åke
    NMR Study of the Motion of Water Molecules in the Natural Zeolite Bikitaite1989In: Journal of Physical Chemistry Solids, Vol. 50, p. 107-Article in journal (Refereed)
  • 245.
    Larsson, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tian, Yuan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Effect of surface termination on the reactivity of nano-sized diamond particle surfaces for bio applications2018In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 134, p. 244-254Article in journal (Other academic)
    Abstract [en]

    Nanodiamond has displayed some unique physical and chemical properties compared to bulk diamond, which broadens its applications invarious areas. The here presented investigations have focused on the combined effect of diamond surface planes and termination on surface reactivity. Then especially towards adhered important biomolecules for bone regeneration and vascularization. Moreover, a more detailed picture of nanodiamond quantum confinements is still missing from a theoretical point of view. An evaluation of realistic models for nano-diamond (ND) particles of various sizes will here be presented. In addition, the adhesions of various biomolecules, both in vacuum and in a liquid environment, as a function of surface plane and termination, will also be presented. It was shown possible to model nanodiamond particles of size larger than 2 nm with (100) and (111) surface planes. For the situation with biomolecule adhesion to the nanodiamond surfaces, there is a large similarity between the results for the diamond (111) and (100)-2x1surfaces. For both of these surfaces, even though the water solvation will create much stronger biomolecular adhesion energies, there is a resemblance in order of adhesion energy for the various systems (i.e., solvated vs. non-solvated).

  • 246. Lauridsen, J.
    et al.
    Eklund, P.
    Jensen, J.
    Furlan, Andrej
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Flink, A.
    Andersson, A. M.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Hultman, L.
    Effects of A-elements (A=Si, Ge or Sn) on the structure and electrical contact properties of Ti-A-C-Ag nanocomposites2012In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 520, no 16, p. 5128-5136Article in journal (Refereed)
    Abstract [en]

    Ti-A-C-Ag (A is Si, Ge or Sn) nanocomposite coatings have been deposited by dc magnetron sputtering in an ultra high vacuum chamber. Electron microscopy, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and x-ray diffraction show that all coatings contain nanocrystalline TiC and Ag grains in a matrix of mainly amorphous C. A C/Ti ratio above unity yields a homogenous distribution of Ag with a reduced grain size. From a chemical point of view. the addition of Ge and Sn to the Ti-C-Ag system should increase the conductivity of the coatings since the formation of m