Defect Chemistry of Donor‐Doped BaTiO3

Abstract

Donor additions to BaTiO₃ up to a few tenths atom percent are compensated by electrons and the resulting electrical conductivity is independent of temperature and Po₂ at 700° to 1000°C. The conductivities are impurity-insensitive at very low Poz and high temperature where reduction is the major source of defects. Variation in the site occupation ratio (A/B in ABO₃ has a small effect on the conductivities for donor additions in the 100 ppm range. Nb is more effective as a donor than is Al as an acceptor, and Nb can compensate approximately 2½ times as much Al on an atomic basis.