The electrical conductivity, σ, and thermoelectric power, S, of pressed pellets of Li3VO4 and Na3VO4 were studied between 440K and the melting point of each solid. The ionic (σi) and electronic (σe) contributions to σ were separated over the entire temperature range with the help of time dependence study of the direct-current electrical conductivity. Super-ionic phases in all 3 solids were observed well below their melting point in which the conductivity was almost purely ionic. The value of the phase transition temperature below, which the solid transforms from super-ionic to normal phase, was obtained. It was shown that in the normal phase, these solids were mixed conductors. Data for the temperature variations of both σi and σe were also presented.

Ionic and Electronic Conductivity in Some Alkali Vanadates. K.M.Mishra, A.K.Lal, F.Z.Haque: Solid State Ionics, 2004, 167[1-2], 137-46