Doping effect of Sr2+ on electrical conductivity in La1-xSrxSc1-yAlyO3 perovskite-type oxides

The total electrical conductivities of Sr2+ and Al3+-doped LaScO3 materials, La1-xSrxSc1-yAlyO3 (x = 0.1-0.325, y = 0-0.01), were examined under wet, dry, reduced and oxidized conditions and were found to express mixed ionic and electronic conductivities. In the high temperature range of 1073 to 1273 K, oxide-ion conduction was predominant. In the systematic measurement of electrical conductivity, we found that the oxide-ion conductivities and activation energies show continuous changes over a wide range of Sr2+ dopant concentrations. We also found that oxide-ion conduction was enhanced by Sr2+ doping to the La3+ site. The ionic transference number, t(ion), calculated from the conductivity data under high and low P (O-2) conditions was 0.73 (x = 0.1-0.325, y = 0.01) at 1273 K.