skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Composition and temperature dependent phase transitions in Co-W double perovskites, a synchrotron X-ray and neutron powder diffraction study

Abstract

High-resolution synchrotron and neutron powder diffraction techniques were used to determine precise structures for the series of perovskite oxides A{sub 2-x}Sr{sub x}CoWO{sub 6} (A=Ca, or Ba, 0=<x=<2). The studies demonstrated that the symmetry decreases as the average size of the A-site cation decreases with a sequential introduction of in-phase and out-of-phase tilting of the BO{sub 6} octahedra. A cubic structure in Fm3-bar m with rock-salt like ordering of the Co and W cations was formed for Ba{sub 2-x}Sr{sub x}CoWO{sub 6} with x{approx}<1.4. As the Sr content was increased, the materials became tetragonal in I4/m and ultimately monoclinic in P2{sub 1}/n. A mixture of monoclinic and tetragonal phases occurs in Sr{sub 2}CoWO{sub 6} at room temperature but this was purely monoclinic at 20K.

Authors:
 [1];  [2];  [3]
  1. Faculty of Science, School of Chemistry, Centre for Structural Biology and Structural Chemistry, University of Sydney, Chemistry Building (F11), Sydney, New South Wales 2006 (Australia)
  2. Faculty of Science, School of Chemistry, The Centre for Structural Biology and Structural Chemistry, University of Sydney, Chemistry Building (F11), Sydney, New South Wales 2006 (Australia), E-mail: kennedyb@chem.usyd.edu.au
  3. Bragg Institute, ANSTO, Menai, New South Wales 2234 (Australia)
Publication Date:
OSTI Identifier:
21015681
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 180; Journal Issue: 2; Other Information: DOI: 10.1016/j.jssc.2006.10.038; PII: S0022-4596(06)00568-8; Copyright (c) 2006 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; BARIUM COMPOUNDS; CALCIUM COMPOUNDS; CATIONS; COBALT COMPOUNDS; CUBIC LATTICES; MIXTURES; MONOCLINIC LATTICES; NEUTRON DIFFRACTION; OXIDES; PEROVSKITE; PHASE TRANSFORMATIONS; STRONTIUM COMPOUNDS; SYMMETRY; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TETRAGONAL LATTICES; TUNGSTEN COMPOUNDS; X RADIATION

Citation Formats

Zhou Qingdi, Kennedy, Brendan J., and Elcombe, Margaret M. Composition and temperature dependent phase transitions in Co-W double perovskites, a synchrotron X-ray and neutron powder diffraction study. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2006.10.038.
Zhou Qingdi, Kennedy, Brendan J., & Elcombe, Margaret M. Composition and temperature dependent phase transitions in Co-W double perovskites, a synchrotron X-ray and neutron powder diffraction study. United States. doi:10.1016/j.jssc.2006.10.038.
Zhou Qingdi, Kennedy, Brendan J., and Elcombe, Margaret M. Thu . "Composition and temperature dependent phase transitions in Co-W double perovskites, a synchrotron X-ray and neutron powder diffraction study". United States. doi:10.1016/j.jssc.2006.10.038.
@article{osti_21015681,
title = {Composition and temperature dependent phase transitions in Co-W double perovskites, a synchrotron X-ray and neutron powder diffraction study},
author = {Zhou Qingdi and Kennedy, Brendan J. and Elcombe, Margaret M.},
abstractNote = {High-resolution synchrotron and neutron powder diffraction techniques were used to determine precise structures for the series of perovskite oxides A{sub 2-x}Sr{sub x}CoWO{sub 6} (A=Ca, or Ba, 0=<x=<2). The studies demonstrated that the symmetry decreases as the average size of the A-site cation decreases with a sequential introduction of in-phase and out-of-phase tilting of the BO{sub 6} octahedra. A cubic structure in Fm3-bar m with rock-salt like ordering of the Co and W cations was formed for Ba{sub 2-x}Sr{sub x}CoWO{sub 6} with x{approx}<1.4. As the Sr content was increased, the materials became tetragonal in I4/m and ultimately monoclinic in P2{sub 1}/n. A mixture of monoclinic and tetragonal phases occurs in Sr{sub 2}CoWO{sub 6} at room temperature but this was purely monoclinic at 20K.},
doi = {10.1016/j.jssc.2006.10.038},
journal = {Journal of Solid State Chemistry},
number = 2,
volume = 180,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}