Defect structure of quenched γ-BINIVOX

The defect structure of gamma-Bi(2)V(0.9)Ni(0.1)O(5.35) (BINIVOX, x = 0.10) quenched from high temperature has been refined using X-ray and neutron powder diffraction data. The defect structure shows that oxide ion vacancies are exclusive to the equatorial positions around the Ni/V atom. Consideration of site occupancies, inter-site contact distances, and geometrical constraints yields two likely coordination environments for V/Ni, i.e. distorted tetrahedral and distorted octahedral. The percentage of V/Ni sites that are distorted tetrahedra may be calculated as 68% with the remainder as distorted octahedra. (C) 1998 Elsevier Science B.V. All rights reserved.