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Title: Temperature dependence of structural parameters in oxide-ion-conducting Nd{sub 9.33}(SiO{sub 4}){sub 6}O{sub 2}: single crystal X-ray studies from 295 to 900K

Crystallographic space group, structural parameters and their thermal changes in oxide-ion-conducting Nd{sub 9.33}(SiO{sub 4}){sub 6}O{sub 2} were investigated using high-temperature single-crystal X-ray diffraction experiments in the temperature range of 295=<T=<900K. The title compound has the apatite structure (space group P6{sub 3}/m), and no notable structural change occurred over the temperature range examined. Observed anisotropy in thermal motions of oxide ions which belong to SiO{sub 4} tetrahedron indicated high rigidity of the tetrahedron in the structure, indicating that they form sp3 hybrid orbitals and the ligand oxygens do not take part in oxide-ion conductivity. Virtually full occupation of the 6h Nd site and highly anisotropic displacements of oxide ion inside the hexagonal channel were maintained over the temperature range examined. This result confirms that oxide-ion transport inside the hexagonal channel is the dominant process of conduction in the title compound.
Authors:
 [1] ;  [2] ;  [3] ;  [3] ;  [3]
  1. Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, DE-70569 Stuttgart (Germany). E-mail: h.okudera@fkf.mpg.de
  2. Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)
  3. Material Science and Engineering, Graduate School of Engineering, Hokkaido University, N13, W8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)
Publication Date:
OSTI Identifier:
20655411
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 177; Journal Issue: 12; Other Information: DOI: 10.1016/j.jssc.2004.09.024; PII: S0022-4596(04)00524-9; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANISOTROPY; APATITES; CRYSTALLOGRAPHY; HEXAGONAL LATTICES; IONS; LIGANDS; MONOCRYSTALS; NEODYMIUM SILICATES; OXIDES; SPACE GROUPS; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; X RADIATION; X-RAY DIFFRACTION