PROCESSING AND ELECTRICAL-PROPERTIES OF ALKALINE EARTH-DOPED LANTHANUM GALLATE

Alkaline earth-doped lanthanum gallate powders were prepared by glycin e/nitrate combustion synthesis. Compacts of powders synthesized under fuel-rich conditions were sintered to densities greater than 97% of th eoretical. Appropriate doping with Sr or Ba on the A-site of the perov skite structure, and Mg on the B-site, resulted in oxygen ion conducti vity higher than that of yttria-stabilized zirconia (YSZ), and high io nic transference numbers. Doping with Ca and Mg resulted in lower cond uctivity than YSZ. Thermal expansion coefficients of the doped gallate s were higher than that of YSZ.