MANGANESE-DOPED BISMUTH VANADATE SOLID ELECTROLYTES .2. ELECTRICAL-CONDUCTIVITY OF BI2V1-XMNXO5.5-X

The total electrical conductivities of a series of manganese-substitut ed-bismuth vanadates, (Bi2V1-xMnxO5.5-x;0.15 less than or equal to x l ess than or equal to 0:25) with the tetragonal (gamma) structure have been measured using two-probe ac impedance spectroscopy. The conductiv ity data do not show simple Arrhenius behaviour. A linear variation of log(sigma T) vs. 1/T is observed at low and high temperatures but at intermediate temperatures some curvature is apparent in the data, part icularly when x=02. Changes in conductivity with p(O-2) indicate that the materials have mixed conductivity. Activation energies and pre-exp onential factors for the linear regions have been determined for selec ted compositions at various p(O-2) values. The total conductivity vari es little with the extent of substitution of V by Mn. The results are compared with data for other gamma-BIMEVOX systems.