The defect structure of the Mg-substituted solid electrolyte was studied by means of high-resolution powder neutron diffraction. The general formula for the solid solutions assumed complete oxidation of the V to VV. Analysis of the neutron diffraction data revealed the defect structure, and indicated that there was partial reduction of V to VIV. The extent of reduction depended upon the thermal history, with high-temperature quenched samples exhibiting a greater degree of reduction than did exponentially slow-cooled samples. This was correlated with differences in the electrical behaviour at low and high temperatures. The differences in ionic conductivity and activation energies between samples having differing thermal histories were explained in terms of a balance between charge-carrier concentration and the extent of defect-trapping effects.

Defect Structure and Ionic Conductivity as a Function of Thermal History in BIMGVOX Solid Electrolytes. I.Abrahams, F.Krok, M.Malys, A.J.Bush: Journal of Materials Science, 2001, 36[5], 1099-104