Structure and crystal chemistry of fluorite-related Bi38Mo7O78 from single crystal x-ray diffraction and ab initio calculations
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Date
2009-06
Journal Title
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Publisher
Elsevier
Abstract
The floating-zone furnace method was used to synthesize single crystals of the fluorite-related delta-Bi2O3-type phase Bi(3)gMo(7)O(78) for the first time. Single crystal synchrotron X-ray diffraction data, in conjunction with ab initio (density functional theory) calculations, were used to solve, optimize, and refine the 5 x 3 x 3 commensurate superstructure of fluorite-type delta-Bi2O3 in Pbcn (a = 28.7058(11) angstrom, b = 16.8493(7) angstrom and c = 16.9376(6) angstrom, Z = 4, R-F= 11.26%, wR(I) = 21.67%). The structure contains stepped channels of Mo6+ in tetrahedral environments along the b axis and chains of Mo6+ in octahedral environments along the ac plane. The role of the stepped channels in oxide ion conduction is discussed. The simultaneous presence of both tetrahedral and octahedral coordination environments for Mo6+, something not previously observed in Mo6+-doped delta-Bi2O3-type phases, is supported by charge balance considerations in addition to the results of crystallographic and ab initio analysis. © 2009, Elsevier Ltd.
Description
Keywords
Neutron diffraction, Conductor devices, Bismuth, X-ray diffraction, Fluorite, Crystal structure
Citation
Sharma, N., Macquart, R. B., Christensen, M., Avdeev, M., Chen, Y. S., & Ling, C. D. (2009). Structure and crystal chemistry of fluorite-related Bi38Mo7O78 from single crystal x-ray diffraction and ab initio calculations. Journal of Solid State Chemistry, 182(6), 1312-1318. doi:10.1016/j.jssc.2009.02.030