Electrical Properties of Cerium‐Doped BaTiO ₃

Abstract

The high‐temperature equilibrium electrical conductivity of Ce‐doped BaTiO 3 was studied in terms of oxygen partial pressure, P (O 2 ), and composition. In (Ba 1−x Ce x )TiO 3 , the conductivity follows the −1/4 power dependence of P (O 2 ) at high oxygen activities, which supports the view that metal vacancies are created for the compensation of Ce donors, and is nearly independent of P (O 2 ) where electron compensation prevails at low P (O 2 ). When Ce is substituted for the normal Ti sites, there is no significant change in conductivity behavior compared with undoped BaTiO 3 , indicating the substitution of Ce as Ce 4+ for Ti 4+ in Ba(Ti 1−y Ce y )O 3 . The Curie temperature ( T c ) was systematically lowered when Ce 3+ was incorporated into Ba 2+ sites, whereas the substitution of Ce 4+ for Ti 4+ sites resulted in no change in this parameter.