Reversible Weight Change of Acceptor‐Doped BaTiO ₃

Abstract

The oxygen vacancy concentration of BaTiO 3 doped with acceptors (Cr to Ni) is determined gravimetrically as a function of the O 2 partial pressure during and after annealing at 700° to 1300°C. The oxygen vacancy concentration of these materials is larger than that of undoped and donor‐doped BaTiO 3 . The oxygen vacancies are doubly ionized and they compensate the acceptors of lower valence. Both the vacancy concentration and the valence of the acceptor dopants depend on the annealing conditions. The electronic energy levels of the acceptors within the BaTiO 3 band gap are derived from the gravimetric measurements. The electrical properties of the acceptor‐doped ceramics are favorable for base‐metal‐electrode multilayer capacitors, which require sintering in reducing atmospheres.