Structure and crystal chemistry of fluorite-related Bi{sub 38}Mo{sub 7}O{sub 78} from single crystal X-ray diffraction and ab initio calculations

Journal Article · Mon Jun 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.02.030· OSTI ID:21370415

Sharma, Neeraj ^[1]; Macquart, Rene B ^[1]; Christensen, Mogens; Avdeev, Maxim ^[2]; Yusheng, Chen ^[3]; Ling, Chris D ^[1]

---

1. School of Chemistry, University of Sydney, Sydney, NSW 2006 (Australia)
2. Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)
3. ChemMatCars, Advanced Photon Source, Argonne National Laboratories, Argonne, IL 60439 (United States)

The floating-zone furnace method was used to synthesize single crystals of the fluorite-related delta-Bi{sub 2}O{sub 3}-type phase Bi{sub 38}Mo{sub 7}O{sub 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 5x3x3 commensurate superstructure of fluorite-type delta-Bi{sub 2}O{sub 3} in Pbcn (a=28.7058(11) A, b=16.8493(7) A and c=16.9376(6) A, Z=4, R{sub F}=11.26%, wR{sub I}=21.67%). The structure contains stepped channels of Mo{sup 6+} in tetrahedral environments along the b axis and chains of Mo{sup 6+} 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 Mo{sup 6+}, something not previously observed in Mo{sup 6+}-doped delta-Bi{sub 2}O{sub 3}-type phases, is supported by charge balance considerations in addition to the results of crystallographic and ab initio analysis. - Graphical abstract: The crystal structure of Bi{sub 38}Mo{sub 7}O{sub 78} with MoO{sub 4} and MoO{sub 6} represented as polyhedra, Bi atoms as gray spheres, and fluorite-type O atoms as white vertices of Bi-O-Bi bonds.

• OSTI ID: 21370415
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 6; Other Information: DOI: 10.1016/j.jssc.2009.02.030; PII: S0022-4596(09)00089-9; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BISMUTH OXIDES
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
DENSITY FUNCTIONAL METHOD
DOPED MATERIALS
MOLYBDENUM IONS
MOLYBDENUM OXIDES
MONOCRYSTALS
SPHERES
X-RAY DIFFRACTION
BISMUTH COMPOUNDS
CALCULATION METHODS
CHALCOGENIDES
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTALS
DIFFRACTION
IONS
MATERIALS
MOLYBDENUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS
VARIATIONAL METHODS