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  • 351.
    Palmquist, Jens-Petter
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Czigany, Z
    Odén, M
    Neidhart, J
    Hultman, L
    Jansson, Ulf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Magnetron sputtered W-C films with C60 as carbon source2003In: Thin Solid Films, no 444, p. 29-37Article in journal (Refereed)
  • 352.
    Palmquist, Jens-Petter
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Czigány, Z
    Hultman, L
    Jansson, Ulf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Epitaxial growth of tungsten carbide films using C60 as carbon precursor2003In: Journal of Crystal Growth, no 259, p. 12-17Article in journal (Refereed)
  • 353.
    Palmquist, Jens-Petter
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorgansik kemi.
    Jansson, Ulf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Birch, J
    Hultman, L
    Isberg, P
    Seppänen, T
    Method of Synthesising a Compound of the Formula Mn+1AXn, Film of the Compound and Its Use2003Patent (Other (popular scientific, debate etc.))
  • 354.
    Palmquist, Jens-Petter
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Jansson, Ulf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Seppanen, T.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Persson, P.O.A.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Birch, J.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Hultman, L.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Isberg, P.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Magnetron sputtered epitaxial single-phase Ti3SiC2 thin films2002In: Applied Physics Letters, Vol. 81, no 5, p. 835-837Article in journal (Refereed)
    Abstract [en]

    We report on the synthesis and characterization of epitaxial single-crystalline Ti3SiC2 films (Mn + 1AXn-phase). Two original deposition techniques are described, (i) magnetron sputtering from Ti3SiC2 compound target and (ii) sputtering from individual titanium and silicon targets with co-evaporated C60 as carbon source. Epitaxial Ti3SiC2 films of single-crystal quality were grown at 900 °C with both techniques. Epitaxial TiC(111) deposited in situ on MgO(111) by Ti sputtering using C60 as carbon source was used to nucleate the Ti3SiC2 films. The epitaxial relationship was found to be Ti3SiC2(0001)//TiC(111)//MgO(111) with the in-plane orientation Ti3SiC2[100]//TiC[101]//MgO[101].

  • 355.
    Palmquist, Jens-Petter
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics IV. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Li, S.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Persson, O. A.
    Emmerlich, J.
    Wilhelmsson, Ola
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics IV. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Högberg, H.
    Katsnelson, M. I.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics IV. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Johansson, B.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics IV. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Ahuja, R.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics IV. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Eriksson, O.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics IV. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Hultman, L.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Physics IV. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Mn+1AXn phases in the Ti-Si-C system studied by thin-film synthesis and ab initio calculations2004In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 70, no 16, p. 165401-Article in journal (Refereed)
    Abstract [en]

    Received 3 November 2003; published 1 October 2004

    Thin films of Mn+1AXn layered compounds in the Ti-Si-C system were deposited on MgO(111) and Al2O3(0001) substrates held at 900°C using dc magnetron sputtering from elemental targets of Ti, Si, and C. We report on single-crystal and epitaxial deposition of Ti3SiC2 (the previously reported MAX phase in the Ti-Si-C system), a previously unknown MAX phase Ti4SiC3 and another type of structure having the stoichiometry of Ti5Si2C3 and Ti7Si2C5. The latter two structures can be viewed as an intergrowth of 2 and 3 or 3 and 4 M layers between each A layer. In addition, epitaxial films of Ti5Si3Cx were deposited and Ti5Si4 is also observed. First-principles calculations, based on density functional theory (DFT) of Tin+1SiCn for n=1,2,3,4 and the observed intergrown Ti5Si2C3 and Ti7Si2C5 structures show that the calculated difference in cohesive energy between the MAX phases reported here and competing phases (TiC, Ti3SiC2, TiSi2, and Ti5Si3) are very small. This suggests that the observed Ti5Si2C3 and Ti7Si2C5 structures at least should be considered as metastable phases. The calculations show that the energy required for insertion of a Si layer in the TiC matrix is independent of how close the Si layers are stacked. Hardness and electrical properties can be related to the number of Si layers per Ti layer. This opens up for designed thin film structures the possibility to tune properties.

  • 356.
    Paun, Cristina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Sá, Jacinto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Continuous-Flow Hydrogenation of D-Xylose with Bimetallic Ruthenium Catalysts on Micrometric Alumina2017In: Synthesis and Catalysis: Open Access, Vol. 2, no 1Article in journal (Refereed)
    Abstract [en]

    Continuous-flow hydrogenation of D-xylose to xylitol was evaluated with pristine and silver modified ruthenium supported on micrometric alumina. The original size of alumina support is required for direct use in flow hydrogenation since it prevents setup clogging. The parent ruthenium catalyst shows high activity and selectivity to the desired product. However, there was an evident competition between adsorption of substrate and product desorption, and ruthenium nanoparticles aggregation. In situ modification of the parent catalyst with silver improved catalysts stability and minimize the competitive adsorption behavior between reactant and product.

  • 357.
    Perre, Emilie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Bryngelsson, Hanna
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Simon, P
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Cu2Sb as anode material integrated into nano-structured Cu current collectors2008In: presented at the 14th International Meeting on Lithium Batteries (IMLB-14) conference in Tianjin, China, 22-28 June 2008, 2008Conference paper (Refereed)
  • 358.
    Perre, Emilie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Simon, P
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Growth of Aluminium Current Collectors for 3-Dimensional Microbattery Applications2008In: presented at the 14th International Meeting on Lithium Batteries (IMLB-14) conference in Tianjin, China, 22-28 June 2008., 2008Conference paper (Refereed)
  • 359.
    Perre, Emilie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Taberna, Pierre-Louis
    CIRIMAT, Université Paul Sabatier, Toulouse, France.
    Simon, Patrice
    CIRIMAT, Université Paul Sabatier, Toulouse, France.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Direct electrodeposition of aluminium nano-rods2008In: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 10, no 10, p. 1467-1470Article in journal (Refereed)
    Abstract [en]

    Electrodeposition of aluminium within an alumina nano-structured template, for use as high surface area current collectors in Li-ion microbatteries, was investigated. The aluminium electrodeposition was carried out in the ionic liquid 1-ethyl-3-methylimidazolium chloride:aluminium chloride (1:2 ratio). First the aluminium electrodeposition process was confirmed by combined cyclic voltammetry and electrochemical quartz crystal microbalance measurements. Then, aluminium was electrodeposited under pulsed-potential conditions within ordered alumina membranes. A careful removal of the alumina template unveiled free standing arrays of aluminium nano-rods. The nano-columns shape and dimensions are directly related to the template dimensions. To our knowledge, this is the first time that direct electrodeposition of aluminium nano-pillars onto an aluminium substrate is reported.

  • 360.
    Petrini, Daniel
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Larsson, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    A theoretical approach to the energetic stability and geometry of hydrogen and oxygen terminated diamond (100) surfaces2006In: Engineering for Manufacturing Applications. Symposium (Materials Research Society Symposium Proceedings Vol.890, 2006, p. 265-271Conference paper (Refereed)
  • 361.
    Petrini, Daniel
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Larsson, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Electron-Transfer Doping on a (001) Surface of Diamond: Quantum Mechanical Study2005In: Journal of Physical Chemistry B, Vol. 109, no 47, p. 22426-22431Article in journal (Refereed)
    Abstract [en]

    The electron-transfer process from an H-terminated diamond (001) surface to an acidic water adlayer, leaving an induced p-type doping in the carbon layers, has been studied using first-principal density functional theory (DFT). The effect of various oxygen-containing species adsorbed to the surface (in the form of an OH group and an oxygen atom in both the ether and ketone positions) on the possibility for electron transfer was also investigated. The results show that a perfect H-termination, as well as the presence of one OH group (equivalent to a surface coverage of approximately 8%), will give an electron transfer of 1.76 and 1.89 e, respectively. There will then be a transfer of electrons from the upper diamond valence band to the lowest unoccupied level in the adsorbate. A corresponding percentage of 8 (Oketone) and 17 (Oether) will effectively hinder the electron-transfer process from occurring.

  • 362.
    Petrini, Daniel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Origin of the reactivity on the nonterminated (100), (110), and (111) diamond surfaces: An electronic structure DFT study2008In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 112, no 37, p. 14367-14376Article in journal (Refereed)
    Abstract [en]

    The reactivity of nonterminated diamond low-index surfaces has been evaluated using density functional theory (DFT). The intrinsic electronic structures of the topmost carbon atoms of diamond (100)-1 x 1, (100)-2 x 1, (110)-1 x 1, (111)-1 x 1, and (111)-2 x 1 surfaces have been calculated and analyzed using highly accurate numerical basis set first-principle techniques. The following reactivity indicators have been utilized: Fukui functions, electrostatic potential, and Kohn-Sham orbitals (highest occupied and lowest unoccupied). Their spatial representations have been mapped onto a charge density isosurface whereby plausible reactive sites were identified and related. Specifically, the change in chemically reactivity induced by a I x I to 2 x I surface reconstruction has been discussed. In addition, density of states and the deformation density of the topmost carbon atoms have been included. Most often the sites of electrophilically susceptible areas correspond to the mapping of f(-) function, electrostatic potential, and highest occupied molecular orbital. Conversely, nucleciphilic sites correspond to the f(+)-function and the lowest unoccupied molecular orbital. However, some discrepancies are found, and it seems that the Fukui functions yield more accurate results due to orbital relaxation effects taken into account. The results herein were furthermore compared to adsorption Studies of H-, O-, and OH-terminated diamond (100) and (I 11) surfaces, respectively. It was concluded that the reactivity of diamond surfaces can be evaluated by using DFT techniques, which will thereby make it possible to increase the knowledge about thin film growth mechanisms, Surface functionalization, and reconstructions.

  • 363.
    Petrini, Daniel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Theoretical study of the thermodynamic and kinetic aspects of terminated (111) diamond surfaces2008In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 112, no 8, p. 3018-3026Article in journal (Refereed)
    Abstract [en]

    Diamond surface susceptibility toward the degree and type of termination and reconstruction has been investigated theoretically by using density functional theory methods. The adsorption geometries and energies for H, O, and OH species adsorbed to diamond (111)-1 x 1 and (111)-2 x 1 surfaces under varying surface coverage were studied and compared with corresponding processes on the diamond (100)-2 x 1 surface. Furthermore, the energy barrier for the diamond (111)-1 x 1 to (111)-2 x 1 surface reconstruction for non-, H-, and O-terminated surfaces were also investigated using first-principle synchrotron transit methodologies. The results show that the adsorption energies for H, O, and OH are -4.53, -5.28, and -4.15 eV, respectively, for 100% terminated diamond (111)-1 x 1 surfaces and -3.29, -3.82, and -2.77 eV, respectively, for the diamond (111)-2 x 1 surfaces. Adsorption of 0 was found to be most energetically favorable in the on-top position on the 1 x 1 surface and in the bridge position on the 2 x 1 surface. The OH groups showed less-favorable adsorption energies in comparison to H and O. The calculations also show that the I x I surface configuration is energetically stable against transformation to the 2 x 1 configuration (of type Pandey chain) with a correspondingly small energy barrier; 0.32 eV. For this specific direction of surface reconstruction, significantly higher barriers were found for the H- and O-terminated diamond surfaces (58.4 and 44.0 eV, respectively). Plausible explanations for these observations are that the surface C-H and C-O bonds must be disrupted for the 2 x 1 (Pandey chain) reconstruction to occur.

  • 364. Piglmayer, K
    et al.
    Lindstam, M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Boman, Mats
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Photon-enhanced surface dissociation effects in laser photolysis of amorphous carbon from CH2I22001In: Surface Review and Letters, Vol. 8, no 6, p. 609-612Article in journal (Refereed)
  • 365.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Jansson, K
    Ekstrand, Åsa
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Solution Route to Metal-Alumina nano composites2005In: 13:th International Workshop on Gels and Glasses, Los Angeles, 2005, 2005, p. 2-Conference paper (Refereed)
  • 366.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, GunnarUppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Alkoxide Based Sol-Gel Processing of CMR Manganites2005Conference proceedings (editor) (Refereed)
  • 367.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Nuclear and Particle Physics. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Alkoxide Based Sol-Gel Processing of CMR Manganites2005In: Materials Research Society Vol. 848: Solid-State Chemistry of Inorganic Materials V, 2005Conference paper (Refereed)
    Abstract [en]

    We have prepared a soluble manganese alkoxide, and used in the first all-alkoxide synthesis of Ca, Sr, and Ba substituted lanthanum manganites. The phase development from gel to target oxide was monitored by TGA, DSC, powder-XRD, FT¨CIR spectroscopy, and TEM-EDS. Here we present the effect of dopant on the phase development. It was found that the dopants influence the temperature of complete oxide formation (¡Ý650¡ãC). The main difference in phase evolution was seen in the 300-600¡ãC range, where the formation of crystalline phases in trace quantities seemed to temporarily reduce the elemental homogeneity.

  • 368.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Alkoxide Route to La0.5Sr0.5CoO3 Films and Powders2005In: Journal of the American Ceramic Society, Vol. 88, no 8, p. 2099-2105Article in journal (Refereed)
    Abstract [en]

    An all-alkoxide route to films and nano-phase powders of the La0.5Sr0.5CoO3 perovskite is described. To our knowledge, this is the first purely alkoxide-based route to (La1xSrx)CoO3, and it yields phase-pure and elementally homogeneous perovskite at 700°C by heating at 2°C/min. At 700°C, a cubic unit cell was obtained with ac=3.853Å, and after further heating to 1000°C, a rhombohedral cell could be indexed: ar=5.417 Å, r=59.94°. Ninety to 130 nm thick films of La0.5Sr0.5CoO3 were obtained by spin coating. The gel-to-oxide conversion was studied in some detail, using thermo-gravimetric analysis, differential scanning calorimetry, powder X-ray diffraction, IR spectroscopy, and transmission electron microscope equipped with an energy-dispersive X-ray spectrometer.

  • 369.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Preparation of La1-x(Sr,Ba)xMnO3 Nano-Phase Powders and Films from Alkoxide Precursors2002In: 10th International Ceramics Congress 2002 Proceedings, 2002, p. 453-Conference paper (Refereed)
  • 370.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Jansson, K
    Preparation of La0.67Ca0.33MnO3 Nanophase Powders and Films from Alkoxide Precursors2002In: Chem. Mater., Vol. 14, no 5, p. 1981-1988Article in journal (Refereed)
  • 371.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Jansson, Kazuhiko
    Preparation of La0.75Sr0.25MnO3 Nano-Phase Powders and Films from Alkoxide Precursors2003In: Journal of Sol-Gel Science and Technology, Vol. 26, p. 257-260Article in journal (Refereed)
  • 372.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Kritikos, M
    Preparation, structure, and properties of a new giant manganese oxo-alkoxide wheel, [Mn19O12(OC2H4OCH3)(14)(HOC2H4OCH3)(10)]center dot HOC2H4OCH32001In: CHEMISTRY-A EUROPEAN JOURNAL, ISSN 0947-6539, Vol. 7, no 16, p. 3438-3445Article in journal (Refereed)
    Abstract [en]

    Alkoxides are of great interest as precursors for sol-gel processing of advanced ceramic materials, but there is very little general knowledge about the low-valent 3d-element alkoxides. The novel oxo-alkoxide, [Mn19O12(moe)(14)- (moeH)(10)] . MOEH (MOE =

  • 373.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Lashgari, K
    Ottosson, Mikael
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    La0.5Sr0.5CoO3 electrode films by alkoxide based sol-gel synthesis2005In: 13:th International Workshop on Gels and Glasses, Los Angeles, 2005, 2005, p. 2-Conference paper (Refereed)
  • 374.
    Pohl, Annika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Westin, Gunnar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Ottosson, Mikael
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Porous and dense perovskite films2007In: Nanostructured Materials and Nanotechnology, Vol 28, 2007, p. 153-163Conference paper (Refereed)
    Abstract [en]

    Lao.5Sro.5Co03 (LSCO) and La0.67Ca0.33MnO3 (LCMO) films were prepared by sol-gel techniques and their structural and transport properties investigated. Films were spin-coated onto (001) LaAlO3 (LAO), (001) SrTiO3 (STO), Pt/TiO2/SiO2/Si, and Al2O3 substrates, and ictural properties were investigated using X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM). SEM studies showed that the films were crack-free and adhered well to the substrates. No preferential orientation of the pervoskite films was observed on Si- or Pt/TiCVSiCVSi-substrates, but films deposited on LAO and STO showed good alignment with the substrate. Transport measurements of epitaxial LCMO films show maximum temperature coefficient of resisth (TCR) of 6.1 % K1 aät 241 K and colossal magnetoresistance (CMR) of 32 % a at 246 K. The conductivity of around l .9 mQcm.

  • 375.
    Pálsson, Gunnar K.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Materials Physics.
    Wang, Yun Tao
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    Azofeifa, Daniel
    Centro de investigatción en Ciencia e ingegnería de materiales and escuela de física, universidad de costa rica, san jose, costa rica.
    Raanaei, Hossein
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Materials Physics.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Hjörvarsson, Björgvin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science, Materials Physics.
    Influence of Titanium and Vanadium on the Hydrogen transport through amorphous alumina films2010In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 494, no 1-2, p. 239-244Article in journal (Refereed)
    Abstract [en]

    The influence of titanium and vanadium on the hydrogen transport rate through thin amorphous alumina films is addressed. Only small changes in the transport rate are observed when the Al2O3 are covered with titanium or vanadium. This is in stark contrast to results with a Pd overlayer, which enhances the transport by an order of magnitude. Similarly, when titanium is embedded into the alumina the transport rate is faster than for the covered case but still slower than the undoped reference. Embedding vanadium in the alumina does not yield an increase in uptake rate compared to the vanadium covered oxide layers. These results add to the understanding of the hydrogen uptake of oxidized metals, especially the alanates, where the addition of titanium has been found to significantly enhance the rate of hydrogen uptake. The current findings eliminate two possible routes for the catalysis of alanates by Ti, namely dissociation and effective diffusion short-cuts formed by Ti. Finally, no photocatalytic enhancement was noticed on the titanium covered samples.

  • 376. Qian, L
    et al.
    Norin, L
    Guo, JH
    Sathe, C
    Agui, A
    Jansson, Ulf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Nordgren, J
    Formation of titanium fulleride studied by x-ray spectroscopies1999In: PHYSICAL REVIEW B-CONDENSED MATTER, ISSN 0163-1829, Vol. 59, no 19, p. 12667-12671Article in journal (Other scientific)
    Abstract [en]

    The chemical interaction between titanium and C-60 in coevaporated titanium-fulleride films has been investigated by x-ray photoelectron spectroscopy, (XPS), x-ray absorption spectroscopy (XAS), and x-ray emission spectroscopy. Two titanium-fulleride film

  • 377.
    Qian, L
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Nyberg, M
    Luo, Yi
    Rubensson, JE
    Talyzine, AV
    Sathe, C
    Ding, D
    Guo, JH
    Högberg, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Kambre, T
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Nordgren, J
    Bonding mechanism in the transition-metal fullerides studied by symmetry-selective resonant x-ray inelastic scattering2001In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, ISSN 0163-1829, Vol. 63, no 8, p. 085418-Article in journal (Refereed)
    Abstract [en]

    The bonding between titanium atoms and C-60 has been examined by means of resonant inelastic x-ray scattering. Using the symmetry-selection rules in the scattering process the symmetry of the orbitals involved in the bond formation was determined. It was

  • 378. Quinlan, Ronald A.
    et al.
    Javier, Artjay
    Foos, Edward E.
    Buckley, Leonard
    Zhu, Mingyao
    Hou, Kun
    Widenkvist, Erika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Drees, Martin
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Holloway, Brian C.
    Transfer of carbon nanosheet films to nongrowth, zero thermal budget substrates2011In: Journal of Vacuum Science & Technology B, ISSN 1071-1023, E-ISSN 1520-8567, Vol. 29, no 3, p. 030602-Article in journal (Refereed)
    Abstract [en]

    Carbon-based nanostructures and materials have become a popular subject of research due to their unique thermal, mechanical, electrical, and optical properties. For example, the strong C-C bonds of graphene-based systems allow for excellent thermal conduction at room temperature and the conjugation of the sp(2) lattice enables extremely high electron mobility. However, the use of carbon nanostructures as a component in polymer composites, sensors, mirco-electro-mechanical systems, and both rigid and flexible electronics has been limited by several factors, including the incompatibility with standard photolithography techniques, the high temperatures required for the nanostructure growth, and the presence of-or complication-of removing noncarbon species. Here, the authors report on a novel method for the transfer of carbon nanosheets to a low or zero thermal budget substrate while maintaining their original morphology and electrical properties. Four-point probe measurements' post-transfer shows the retention of in-plane conductivity and scanning electron microscopy reveals the preservation of the original vertical morphology. Raman spectroscopy measurements confirm the retention of the graphitic structure of the post-transfer nanosheet film. This new transfer technique builds on the ability to conformally coat nanosheets while maintaining the original ultrahigh surface area morphology and the ability to fully incorporate nanosheets into several polymers while maintaining the original nanostructure separation. For a demonstration of the usefulness of polymer filling, carbon nanosheets were used as an ultrahigh surface area electrode for the photoactive polymer poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] in proof of principle experiments of a nanosheet-based organic photovoltaic device.

  • 379. Rashid, A
    et al.
    Landström, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Brodoceanu, D
    Piglmayer, K
    Lamp-assisted CVD of carbon micro/nano-structures using metal catalysts and CH2I2 precursor2009In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 255, no 10, p. 5368-5372Article in journal (Refereed)
    Abstract [en]

    Carbon micro/nanofibers and nanotubes were deposited via chemical vapor deposition (CVD) using CH2I2 precursor and different metal catalysts (Pd, Ni, Fe, Co and Mn) on Si (1 0 0) substrates. A versatile and low-cost IR lamp technique is employed to induce the deposition process. With this method carbon features could be obtained already at temperatures much lower than with common techniques. Palladium metal was deposited by laser-assisted CVD from a liquid solution of the ammine complex and the 3d metals by thermal evaporation. Large-scale periodicity of nano-sized metal catalysts, and subsequently of carbon deposits was obtained by using monolayers of polystyrene microspheres as mask. The carbon structures were analyzed by SEM and micro-Raman spectroscopy.

  • 380. Rashid, Abdul
    et al.
    Landström, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Piglmayer, Klaus
    Excimer-Laser Surface Processing in CH2I2 Atmospheres: Simultaneous Localized Etching of Si and Deposition of C2009In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 156, no 4, p. D113-D118Article in journal (Refereed)
    Abstract [en]

    In the present paper, a complex chemical process involving laser-materials interaction within a strong absorbing gas phase is investigated and characterized. The process utilizes excimer laser pulses to dissociate methylene iodide (CH2I2) in the gas phase and to locally heat the surface of a silicon substrate. These effects induce chemical reactions leading to efficient etching of silicon within the laser-irradiated surface area, in combination with simultaneous deposition of carbon material outside. Because of the sensitive behavior of the photoinduced substrate surface temperature on the absorption conditions in the gas phase, model calculations were performed to improve the design of the system and to analyze the observed experimental results.

  • 381.
    Raymand, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Spångberg, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    van Duin, Adri
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Water adsorption beyond monolayer coverage on ZnO surfaces and nanoclusters2008In: SOLAR HYDROGEN AND NANOTECHNOLOGY III / [ed] Westin, G, 2008, Vol. 7044, p. E440-E440Conference paper (Refereed)
    Abstract [en]

    The surface structures of ZnO surfaces and ZnO nanoparticles, with and without water, were studied with a ReaxFF reactive force field (FF) and molecular dynamics (MD) simulations. The force field parameters were fitted to a training set of data points (energies, geometries, charges) derived from quantum-mechanical DFT/B3LYP calculations. The ReaxFF model predicts structures and reactions paths at a fraction of the computational cost of the quantum-mechanical calculations and as such allows dynamical simulations of reactive process for large (>>1000 atoms) and long (> 100 ps) timescales. Our simulations give the following results for the (10 (1) over bar0) surface. (i) The alternating H-bond pattern of Meyer et al. for a single monolayer coverage is reproduced by our simulations. This pattern is maintained at elevated temperatures (COOK). (ii) At coverages beyond one water monolayer we observe enhanced ZnO hydroxylation at the expense of ZnO hydration. (iii) This is achieved through an entirely new H-bond pattern mediated via the water molecules in the second layer above the ZnO surface. (iv) During a water desorption simulation at T=300K we observe that the desorption rate slows significantly when two monolayers remain. (v) Simulations of nanoparticles in the presence and absence of water suggest that water plays a key role in the determination of nanoparticle shape by catalyzing surface reconstruction reactions and stabilizing specific surface structures.

  • 382.
    Razaq, Aamir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Gustav, Nyström
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Maria, Strömme
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Mihranyan, Albert
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    High-capacity Conductive Nanocellulose Paper Sheets for Electrochemically Controlled Extraction of DNA Oligomers2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 12, p. e29243-Article in journal (Refereed)
    Abstract [en]

    Highly porous polypyrrole (PPy)-nanocellulose paper sheets have been evaluated as inexpensive and disposable electrochemically controlled three-dimensional solid phase extraction materials. The composites, which had a total anion exchange capacity of about 1.1 mol kg(-1), were used for extraction and subsequent release of negatively charged fluorophore tagged DNA oligomers via galvanostatic oxidation and reduction of a 30-50 nm conformal PPy layer on the cellulose substrate. The ion exchange capacity, which was, at least, two orders of magnitude higher than those previously reached in electrochemically controlled extraction, originated from the high surface area (i.e. 80 m(2) g(-1)) of the porous composites and the thin PPy layer which ensured excellent access to the ion exchange material. This enabled the extractions to be carried out faster and with better control of the PPy charge than with previously employed approaches. Experiments in equimolar mixtures of (dT)(6), (dT)(20), and (dT)(40) DNA oligomers showed that all oligomers could be extracted, and that the smallest oligomer was preferentially released with an efficiency of up to 40% during the reduction of the PPy layer. These results indicate that the present material is very promising for the development of inexpensive and efficient electrochemically controlled ion-exchange membranes for batch-wise extraction of biomolecules.

  • 383.
    Razaq, Aamir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Mihranyan, Albert
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Welch, Ken
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Influence of the type of oxidant on anion exchange properties of fibrous Cladophora cellulose/polypyrrole composites2009In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 113, no 2, p. 426-433Article in journal (Refereed)
    Abstract [en]

    The electrochemically controlled anion absorption properties of a novel large surface area composite paper material composed of polypyrrole (PPy) and cellulose derived from Cladophora sp. algae, synthesized with two oxidizing agents, iron(III) chloride and phosphomolybdic acid (PMo), were analyzed in four different electrolytes containing anions (i.e., chloride, aspartate, glutamate, and p-toluenesulfonate) of varying size. The composites were characterized with scanning and transmission electron microscopy, N2 gas adsorption, and conductivity measurements. The potential-controlled ion exchange properties of the materials were studied by cyclic voltammetry and chronoamperometry at varying potentials. The surface area and conductivity of the iron(III) chloride synthesized sample were 58.8 m2/g and 0.65 S/cm, respectively, while the corresponding values for the PMo synthesized sample were 31.3 m2/g and 0.12 S/cm. The number of absorbed ions per sample mass was found to be larger for the iron(III) chloride synthesized sample than for the PMo synthesized one in all four electrolytes. Although the largest extraction yields were obtained in the presence of the smallest anion (i.e., chloride) for both samples, the relative degree of extraction for the largest ions (i.e., glutamate and p-toluenesulfonate) was higher for the PMo sample. This clearly shows that it is possible to increase the extraction yield of large anions by carrying out the PPy polymerization in the presence of large anions. The results likewise show that high ion exchange capacities, as well as extraction and desorption rates, can be obtained for large anions with high surface area composites coated with relatively thin layers of PPy.

  • 384.
    Razaq, Aamir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Nyström, Gustav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Carlsson, Daniel O
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strømme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Mihranyan, Albert
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Potential controlled ion-exchange membrane based on high surface area conducting paper composite for DNA separation2011Conference paper (Refereed)
  • 385.
    Razaq, Aamir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Mihranyan, Albert
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Carbon Highways in High Surface Area Conducting Paper Membranes for Efficient DNA Separation.2011In: Hybrid Biological Materials III, JJ9.6. MRS 2011 Spring meeting San Francisco, 2011Conference paper (Refereed)
  • 386.
    Razaq, Aamir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strømme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Mihranyan, Albert
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Electrochemically Controlled Separation of DNA Oligomers with High Surface Area Conducting Paper Electrode2011In: Bioelectronics, Biointerfaces, and Biomedical Applications 4 / [ed] M. Madou, A. Hoff, D. Landheer, L. Nagahara, K. Sode, T. Thundat, C. Wang, Pennington, N.J.: Electrochemical Society, 2011, p. 135-142Conference paper (Refereed)
  • 387.
    Razpet, Alenka
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Physics, Department of Physics and Materials Science, Materials Science. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Jonfysik.
    Johansson, Anders
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Physics, Department of Physics and Materials Science, Materials Science. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Possnert, Göran
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Physics, Department of Physics and Materials Science, Materials Science. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Jonfysik.
    Skupinski, Marek
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Physics, Department of Physics and Materials Science, Materials Science. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Materialvetenskap.
    Hjort, Klas
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences, Ion Physics. Physics, Department of Physics and Materials Science, Materials Science. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Materialvetenskap.
    Hallén, Anders
    Fabrication of high-density ordered nanoarrays in silicon dioxide by MeV ion track lithography2005In: Journal of Applied Physics, Vol. 97, p. 044310-Article in journal (Refereed)
    Abstract [en]

    Self-assembled nanoporous alumina films were employed as masks for MeV ion track lithography. Films with thickness of 2 µm and pore diameters of 30 and 70 nm were attached to thermally grown SiO2 covered with a thin gold layer. The samples were aligned with respect to the beam by detecting backscattered He+ ions with the initial energy of 2 MeV. The ordered pattern of the porous alumina films was successfully transferred into SiO2 after irradiation with a 4 MeV Cl2+ beam at fluence of 1014 ions/cm2, followed by chemical etching in a 5% HF solution.

  • 388.
    Razpet, Alenka
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Jonfysik.
    Possnert, GöranUppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Jonfysik.Johansson, AndersUppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.Abid, MohamedTechnology, Department of Materials Science. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.Hallén, Anders
    Properties of ordered nanoporous alumina as a template for pattern transfer by MeV ion irradiation2004Conference proceedings (editor) (Refereed)
  • 389.
    Razpet, Alenka
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science. Technology, Department of Engineering Sciences, Ion Physics. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. jonfysik.
    Possnert, Göran
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science. Technology, Department of Engineering Sciences, Ion Physics. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. jonfysik.
    Johansson, Anders
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science. Technology, Department of Engineering Sciences, Ion Physics. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Hallén, Anders
    Hjort, Klas
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science. Technology, Department of Engineering Sciences, Ion Physics. Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Materialvetenskap.
    Ion transmission and characterization of ordered nanoporous alumina2004In: Nuclear Instruments and Methods Physics Research, Vol. B, no 222, p. 593-600Article in journal (Refereed)
    Abstract [en]

    Ordered nanoporous alumina samples with a pore diameter of 70 nm, an array period of 100 nm and several thicknesses were considered as possible masks for pattern transfer by MeV ion lithography. A simple procedure for the sample alignment using a 2 MeV He+ beam was utilized. The energy distributions of transmitted ions as well as backscattering spectra were studied in aligned and non-aligned orientations. The best transmission, comparable to the relative surface area covered by pores, was reached for 2 um thick samples and was independent on ion species. Although the transmission for thicker mambranes was generally lower, it significantly depended on the quality of each individual sample. The presented ion beam technique can therefore be used as a tool for the characterization of porous materails. The acceptance angle for transmission through pores and the effective atomic density of samples can be obtained from the experimental data and it is shown that nanoporous alumina can be used as a mask for MeV ion lithography.

  • 390.
    Ronneteg, Sabina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Berger, Rolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    André, G.
    A neutron powder diffraction study of the helimagnetic structure of TlCo2Se2−xSx2010In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 322, no 6, p. 681-685Article in journal (Refereed)
    Abstract [en]

    The magneti clayer structure of TlCo2Se2-xSx has been thoroughly re-investigated with neutron powder diffraction. The cobalt magnetic moments are ferromagnetically arranged with in the layers, but the interlayer coupling differs profoundly with varying composition (x): the spins in TlCo2Se2 form a helix along the c-axis with a turning-angle of similar to 119 degrees at 1.4 K. This kind of helical structure prevails for 0 <= x <= 1.5 with a gradual decrease of the angle with increasing sulphur content, down to 34 degrees, showing an almost linear relationship with the interlayer distance of Co-Co. For x >= 1.75 the interlayer couplingchanges to ferromagnetic. Unexpectedly, two helices were found to coexist at x = 0.5 and x = 1.0. The interaction between adjacent cobalt layers is there characterized by an incommensurate angle (106 degrees, resp., 73 degrees) together with a commensurate angle of 90 degrees. The magnetic structures have been refined as two magnetic phases, each having a characteristic wave vector. A tentative model where the symmetry of the structure and the interlayer distance compete is considered for explaining the simultaneous occurrence of the two kinds of diffraction profile satellites.

  • 391.
    Ronneteg, Sabina
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Technology, Department of Engineering Sciences, Solid State Physics. Oorganisk kemi.
    Berger, Rolf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Technology, Department of Engineering Sciences, Solid State Physics. Oorganisk kemi.
    Felton, S
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Nordblad, P
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. Technology, Department of Engineering Sciences, Solid State Physics. Fasta tillståndets fysik.
    Antiferro- to ferromagnetic transition in TlCo2Se(2-x)S(x)2003In: 14th International Conference on Solid Compounds of Transition Elements: Linz (Austria) July 6-11, 2003, 2003, p. PO I-28Conference paper (Other scientific)
    Abstract [en]

    Materials with the ThCr2Si2 structure type often have many interesting properties, exemplified by silicides and germanides. [...] Neutron powder diffraction experiments on different compositions have been performed and show that the magnetix helix is still obtained even at x= 1.0 (TlCo2SeS). The q-value increases when the distance between the cobalt layers decreases.

  • 392.
    Rooth, Mårten
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Johansson, Anders
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Boman, Mats
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Hårsta, Anders
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Ordered and Parallel Niobium Oxide Nano-Tubes Fabricated using Atomic Layer Deposition in Anodic Alumina Templates2006In: Materials Research Society, Vol. 901, p. 0901-Ra24Article in journal (Refereed)
    Abstract [en]

    Amorphous niobium oxide (Nb2O5) nano-tubes were fabricated inside anodic alumina templates using atomic layer deposition (ALD). The nanoporous templates were in-house fabricated anodic alumina membranes having an inter-pore distance of about 100 nm with pores lengths of 2 µm. The pores were parallel and well ordered in a hexagonal pattern. Atomic layer deposition was performed using gas pulses of niobium iodide (NbI5) and oxygen separated by purging pulses of argon. By employing long gas pulses (30 s) it was possible to get coherent and amorphous Nb2O5 films conformally covering the pore-walls of the alumina template. The outer diameter of the nano-tubes was tailored between 40 and 80 nm by using alumina templates with different pore sizes. By using template membranes with pores not opened in the bottom, nano-tubes with one side closed could be fabricated. Free-standing, and still parallel, nano-tubes could be obtained by selectively etching away the alumina template using phosphoric acid. Using the above mentioned procedure it was possible to fabricate unsurpassed parallel niobium oxide nano-tubes of equal length, diameter and wall-thickness, ordered in a perfect hexagonal pattern. The samples were analysed using high resolution scanning electron microscopy (HR-SEM), transmission electron microscopy (TEM), electron diffraction and x-ray fluorescence spectroscopy (XRFS).

  • 393.
    Rooth, Mårten
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Lindahl, Erik
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Hårsta, Anders
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Atomic Layer Deposition of Co3O4 Thin Films Using a CoI2/O2 Precursor Combination2006In: Chemical Vapor Deposition, Vol. 12, no 4, p. 209-213Article in journal (Refereed)
    Abstract [en]

    Thin films of Co3O4 have been successfully deposited on SiO2/Si(100) and MgO(001) substrates by atomic layer deposition (ALD) using the precursor combination CoI2/O2. The deposition temperature was found to have a strong influence on the growth rate. On SiO2/Si(100) substrates, growth rates of about 0.2 nm per cycle were recorded at 500 °C, decreasing to 0.004 nm per cycle at 700 °C. On MgO(001) substrates the growth rates were lower, reaching about 0.12 nm per cycle at 475 °C, while no growth could be detected at 700 °C. The films were found to grow as the cubic Co3O4 phase throughout the temperature range 475-700 °C, polycrystalline on SiO2/Si(100), and epitaxial on MgO(001). On MgO(001) the epitaxial relationship was established to the in-plane orientation (001)[100]Co3O4||(001)[100]MgO. No iodine could be detected by Rutherford backscattering spectroscopy (RBS) or by X-ray fluorescence (XRF) spectroscopy in any of the deposited films.

  • 394. Rosén, Johanna
    et al.
    Larsson, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Schneider, Jochen M
    Ab initio molecular dynamics study of hydrogen removal by ion–surface interactions2005In: Journal of Physics: Condensed Matter, Vol. 17, p. L137-L142Article in journal (Refereed)
    Abstract [en]

    The energy dependence of surface reactions has been investigated through ab initio MD simulations for collisions between Al1+ and a gibbsite surface. No change in surface composition was observed for 0 eV initial kinetic energy of Al1+. An increase in energy to 3.5 eV resulted in extended surface migration of hydrogen, subsequent H2 formation and desorption from the surface. These results may be understood based on thermodynamics and an increase in entropy upon H2 formation. They are of fundamental importance for an increased understanding of thin film growth through the correlation between ion energy and film composition. They may also indicate a pathway to affect impurity incorporation during film growth.

  • 395.
    Rosén, Johanna
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Schneider, Jochen M
    Larsson, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Ab initio molecular dynamics study of ion-surface interactions2005In: Solid State Communications, Vol. 134, p. 333-336Article in journal (Refereed)
    Abstract [en]

    Ion-surface collisions have been investigated theoretically using ab initio molecular dynamics within density functional theory. The temporal evolution of the position of the bombarding ion, as well as its nearest neighbors, was studied for initial kinetic energies of 0 and 3.5 eV (0 and 5 km/s, respectively). Also investigated was the ion-surface interaction prior to collision and the following energy transfer, as indicated by changes in ion velocity. At 3.5 eV collision energy, the calculation results suggest the formation of local structural disorder within the simulation time frame studied. These results are of fundamental importance for an increased understanding of the ion-surface interaction during a collision event, with resulting changes in atomic level structure.

  • 396. Rosén, Johanna
    et al.
    Schneider, Jochen M
    Larsson, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Ab initio studies of adsorption and migration surface processes on an α-Al2O3 surface2005In: Solid State Communications, Vol. 135, no 1-2, p. 90-94Article in journal (Refereed)
    Abstract [en]

    Surface processes on α-Al2O3 (0001) have been investigated theoretically using density functional theory. Ion–surface interactions prior to collision were investigated by means of ab initio molecular dynamics simulations, showing an adsorbate trajectory towards a preferred adsorption site. Furthermore, the adsorption process at different surface sites was investigated, together with calculations of barriers for migration between these sites. Although the equilibrium (bulk) adsorption site was energetically favourable, the presence and magnitude of the migration barriers indicate that activation energy is necessary to form the equilibrium surface structure. These results are of importance for a fundamental understanding of ion–surface interactions.

  • 397.
    Rosén, Johanna
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Schneider, Jochen M
    Larsson, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Thin Film Growth Related Adsorption Study of Al and O Ions on an -Al2O3 Surface2004In: J. Phys. Chem. B, Vol. 108, p. 19320-19324Article in journal (Refereed)
    Abstract [en]

    The surface reactivity of -Al2O3 (0001) has been investigated theoretically using density functional theory. The adsorption process of Al+, Al2+, Al3+, and O+ were studied to identify possible preferential adsorption sites during thin film growth. Differences in near surface atomic displacements (e.g., adsorption-induced surface reconstructions), energies, and bonding character have been evaluated. The adsorption energies for the metallic ions showed a strong dependence on both initial charge and adsorption site. The O+ ions showed no site dependence, but adsorption energies similar to those calculated for Al+. The results indicate that the adsorption of O+ and Al3+ may favor the formation of an amorphous structure, which is consistent with experimental observations. The results are of fundamental importance for the understanding of thin film microstructure evolution.

  • 398. Rosén, Johanna
    et al.
    Widenkvist, Erika
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Larsson, Karin
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Inorganic Chemistry. oorganisk kemi.
    Kreissig, Ulrich
    Mráz, Stanislav
    Martinez, Carlos
    Music, Denis
    Schneider, J
    Reducing the impurity incorporation from residual gas by ion bombardment during high vacuum magnetron sputtering2006In: Applied Physics Letters, Vol. 88, p. 191905-Article in journal (Refereed)
    Abstract [en]

    The influence of ion energy on the hydrogen incorporation has been investigated for alumina thin films, deposited by reactive magnetron sputtering in an Ar/O2/H2O environment. Ar+ with an average kinetic energy of ~5 eV was determined to be the dominating species in the plasma. The films were analyzed with x-ray diffraction, x-ray photoelectron spectroscopy, and elastic recoil detection analysis, demonstrating evidence for amorphous films with stoichiometric O/Al ratio. As the substrate bias potential was increased from –15 V (floating potential) to –100 V, the hydrogen content decreased by ~70%, from 9.1 to 2.8 at. %. Based on ab initio calculations, these results may be understood by thermodynamic principles, where a supply of energy enables surface diffusion, H2 formation, and desorption [Rosén et al., J. Phys.: Condens. Matter 17, L137 (2005)]. These findings are of importance for the understanding of the correlation between ion energy and film composition and also show a pathway to reduce impurity incorporation during film growth in a high vacuum ambient.

  • 399.
    Ruuska, Henna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Surface reactivities of (111), (100), and (110) planes of c-BN: A quantum mechanical approach2007In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 16, no 1, p. 118-123Article in journal (Refereed)
    Abstract [en]

    Surface reactivities of the three low-index planes (111), (100), and (110) of cubic boron nitride were theoretically investigated using density functional theory under periodic boundary conditions. Surface energies for non-terminated (bulk vs. optimized structure) and H-terminated (optimized structure) surfaces were calculated. The optimized structure is identical to the local low-energy structure closest to the initial bulk geometry. The adsorption process of hydrogen atoms on the various surface planes was also examined. On the basis of these calculations, the orders of reactivities for the cubic BN planes are (110) > (100) > (111) (bulk) and (100) > (110) > (111) (optimized) for non-terminated surfaces. The most reactive form of the (110) surface (i.e. bulk structure) became the most stable one when the surface was completely terminated with H species.

  • 400.
    Råsander, Mikael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Bergman, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Delin, Anna
    Applied Materials Physics, Royal Institute of Technology.
    Sanyal, Biplab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Eriksson, Olle
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Surface and interface properties of graphene on titanium carbide: A first principles studyManuscript (preprint) (Other (popular science, discussion, etc.))
567891011 351 - 400 of 524
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