Electrical conductivity of gamma-Bi2O3-V2O5 solid solution

The total conductivity (sigma(T)) in bcc gamma-Bi2O3 doped with V2O5 system has been measured in the composition range between 1 and 7 mol% V2O5 at different temperatures. Phase transitions for different addition amounts depending on the temperature were investigated by quenching the samples. According to the XRD and DTA/TG results, this bcc type solid solution was stable up to about 720degreesC and the solubility limit was found at similar to7 mol% V2O5 in gamma-phase. This system showed predominantly an oxide ionic conduction. As the V2O5 addition increased, the ionic conduction increased up to 5 mol% V2O5 at which the highest conductivity was found to be 8.318.10(-2) Ohm(-1) cm(-1) at 700degreesC and then decreased. It has been proposed that gamma-Bi2O3 phase contains a large number of oxide anion vacancies and incorporated vanadium cations at tetrahedral sites which affect the oxygen sublattice of the crystal structure.