Crystal Structure, Diffusion Path, and Oxygen Permeability of a PrNiO-Based Mixed Conductor (PrLa )2(NiCuGa.)O.
We have investigated in situ the crystal structure, oxygen diffusion path, oxygen permeation rate, and electrical conductivity of a doped praseodymium nickel oxide, PrNiO-based mixed conductor, (PrLa)2(NiOCuGa)O (PLNCG) in air between 27 °C and 1015.6 °C. The PLNCG has a tetragonal 14/mmm K2N1F4-typ...
| Publicado en: | Journal of the American Chemical Society Vol. 132; no. 7; pp. 2385 - 2393 |
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| Autores principales: | , , |
| Formato: | Artículo |
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American Chemical Society
2/24/2010
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=48616445&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 48616445 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 2/24/2010 vid: 132 iid: 7 pid: 997 pub: American Chemical Society artinfo: ui: 48616445 10.1021/ja909820h ppf: 2385 ppct: 8 formats: tig: atl: Crystal Structure, Diffusion Path, and Oxygen Permeability of a PrNiO-Based Mixed Conductor (PrLa )2(NiCuGa.)O. aug: au: Yashima, Masatomo Sirikanda, Nuansaeng Ishihara, Tatsumi affil: Department of Materials Science and Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-Ku, Yokohama, Kanagawa 226-8502, Japan Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-Ku, Fukuoka, Fukuoka 819-0395, Japan su: Crystallography Electric conductivity Rock salt Rietveld refinement Maximum entropy method Anisotropy Thin films Oxide minerals sug: subj: Crystallography Electric conductivity Rock salt Rietveld refinement Maximum entropy method Anisotropy Thin films Oxide minerals ab: We have investigated in situ the crystal structure, oxygen diffusion path, oxygen permeation rate, and electrical conductivity of a doped praseodymium nickel oxide, PrNiO-based mixed conductor, (PrLa)2(NiOCuGa)O (PLNCG) in air between 27 °C and 1015.6 °C. The PLNCG has a tetragonal 14/mmm K2N1F4-type structure which consists of a (PrLa)(NiCuGa)O perovskite unit and a (PrLa)O rock salt unit in the whole temperature range. Both experimental and theoretica' electron density maps indicated two-dimensional networks of (NiCuGa)-O covalent bonds in PLNCG. Highest occupied molecular orbitals (HOMO) in PLNCG demonstrate that the electron-hole conduction occurs via Ni and Cu atoms in the (NiCuGa)-O layer. The bulk oxygen permeation rate was high (137μmol cm min at 1000 °C), and its activation energy was low (51 kJ mol at 950 °C). The Rietveld method, maximum-entropy method (MEM), and MEM-based pattern fitting analyses of neutron and synchrotron diffraction data indicate a large anisotropic thermal motion of the apical O2 oxygen at the 4e site (0, 0, z z≈ 0.2) in the (PrLa)(NiCuGa)O perovskite unit. Neutron and synchrotron diffraction data and theoretical structural optimization show the interstitial oxygen (O) atom at (x, 0, z) (x≈ 0.6 and z 0.2). The nuclear density analysis indicates that the bulk oxide-ion diffusion, which is responsible for the high oxygen permeation rate, occurs through the interstitial O3 and anisotropic apical O2 sites. The nuclear density at the bottleneck on the oxygen diffusion path increases with temperature and with the oxygen permeation rate. The activation energy from the nuclear density at the bottleneck decreases with temperature, which is consistent with the decrease of the activation energy from oxygen permeation rate. The extremely low activation energy (12 kJ mol at 900 °C) from the nuclear density at the bottleneck indicates possible higher bulk oxygen permeation rates in quality single crystals and epitaxial thin films. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2010 holdings: @attributes: islocal: N |
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