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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/13125
Title: X-ray powder diffraction and electron diffraction studies of the thortveitite-related L phase, (Zn,Mn)2V2O7
Authors: Knowles K.M.
Vickers M.E.
Sil, Anjan
Han Y.-H.
Jaffrenou P.
Published in: Acta Crystallographica Section B: Structural Science
Abstract: The phase designated -Zn3(VO4)2 reported as a minor second phase in zinc oxide-based varistor materials doped with vanadium oxide and manganese oxide is shown to be the L phase, (Zn1 - x Mn x )2V2O7 (0.188 < x < 0.538), in the pseudo-binary Mn2V2O7-Zn2V2O7 system. Analysis of X-ray powder diffraction patterns and electron diffraction patterns of this phase shows that the previously published a, c and Î’ values for this thortveitite-related phase are incorrect. Instead, Rietveld refinement of the X-ray powder pattern of the L phase shows that it has a monoclinic C lattice with Z = 6, with a = 10.3791 (1), b = 8.5557 (1), c = 9.3539 (1) Ã… and Î’ = 98.467 (1)°. Although prior convergent-beam electron diffraction work of -Zn3(VO4)2 confirmed the C Bravais lattice, the space group was found to be Cm rather than C2/m, the difference perhaps arising from the inability of the X-rays to detect small displacements of oxygen. Attempts to refine the structure in Cm did not produce improved R factors. The relationship between the crystal structure of the L phase and the high-temperature C2/m Β′-Zn2V2O7 thortveitite-type solid solution is discussed. © 2009 International Union of Crystallography.
Citation: Acta Crystallographica Section B: Structural Science (2009), 65(2): 160-166
URI: https://doi.org/10.1107/S0108768108042444
http://repository.iitr.ac.in/handle/123456789/13125
Issue Date: 2009
Keywords: Electron diffraction
Thortveitite-related L phase
Varistor materials
X-ray powder diffraction
ISSN: 1087681
Author Scopus IDs: 7005635256
7103389283
7003754102
15834435500
8698333400
Author Affiliations: Knowles, K.M., Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom
Vickers, M.E., Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom
Sil, A., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee 247 667, Uttarakhand, India
Han, Y.-H., Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom
Jaffrenou, P., Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom, Laboratoire D'Etude des Microstructures, ONERA-CNRS, Boit̃e Postale 72, 92322 Chat̃illon CEDEX, France
Corresponding Author: Knowles, K. M.; Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom; email: kmk10@cam.ac.uk
Appears in Collections:Journal Publications [MT]

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