Oxidation of reduced Y-doped semiconducting barium titanate ceramics

Abstract

Oxidation-induced microstructural changes in reduced yttrium-doped barium titanate (Ba1-xYxTi 1-x 4+ Ti x 3+ O3) are studied using samples sintered in a reducing atmosphere (\(p_{O_2}\) = 10−4Pa) and then oxidized in air at 1150 and 1350°C. The results indicate that oxidation leads to precipitation of Ba6Ti17O40 and, at relatively high doping levels, Y2Ti2O7. These phases increase the electrical resistance of the outer layer of the grains in the ceramics.