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On the microstructure of a high-pressure phase of W3O8

Published online by Cambridge University Press:  10 January 2013

D. Louër
Affiliation:
Laboratoire de Cristallochimie, CSIM (URA CNRS 1495)Université de Rennes I, Avenue du Général Leclerc, 35042 Rennes Cedex, France
M. Sundberg
Affiliation:
Department of Inorganic and Structural Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
P.-E. Werner
Affiliation:
Department of Inorganic and Structural Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
V. P. Filonenko
Affiliation:
Institute of High-Pressure Physics, Academy of Sciences of Russia, Troitsk, Moscow Region, Russia
I. P. Zibrov
Affiliation:
Institute of Crystallography, Academy of Sciences of Russia, Leninsky prosp, 59, Moscow 117 333, Russia

Abstract

The structures of two high-pressure tungsten oxides, previously studied by high-resolution electron microscopy, were confirmed by Rietveld refinement based on X-ray powder diffraction data. The phases have identical stoichiometry, W3O8, and extremely narrow 00l reflections in common. The microstructure of the dominant phase was investigated by means of X-ray powder diffraction pattern decomposition. A Williamson–Hall plot revealed that all lines, except the 00l reflections, were broadened solely due to the crystallite size effect. A cylindrical model is used to describe the average form of the coherently diffracting domains. The height of the cylinder, whose axis is colinear with the crystallographic c parameter of both phases, is considered “infinite,” and the average diameter of the cylinder model is 655(22) Å. A quantitative confirmation is obtained from electron microscopy.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1995

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