Quantitative analysis of oxidation-reduction behavior of Mn-doped BaTiO3

Effects of Mn addition on the oxidation-reduction reaction behaviour of BaTiO3 were studied as a function of oxygen partial pressure and temperature. Oxygen vacancy concentration of Mn-doped BaTiO3 significantly increased as the oxygen activity was lowered. The enthalpy of the reduction reaction was estimated from the oxygen vacancy contents at various temperatures and increased with increasing Mn contents. The oxygen vacancy concentration of specimens co-doped with Mg and Mn at room temperature was much lower than that of the singly Mg-doped specimen. It was confirmed that the increased enthalpy of the reduction reaction could suppress the degradation behaviour and improve the reliability of dielectrics with Mn. 21 refs.