Charge compensation mechanisms of BaTiO3 ceramics co-doped with La2O3 and Bi2O3

Doping modification is commonly used to improve the electrical properties of BaTiO3 (BT). In this study, the ((1-x)BT-x(Bi2O3–La2O3)) ceramics were synthesised to investigate the charge balance compensation mechanisms of BT ceramics co-doped with La2O3 and Bi2O3 as donors at A-site. The XRD results showed that a pseudo-cubic phase was formed by intruding dopants. The Raman spectroscopy revealed that the samples, which x = 0.10 and 0.16, had relatively more oxygen and titanium vacancies. After heat-treatment the samples in oxygen atmosphere, the dielectric constant of the sample with x = 0.10 was higher than that of the untreated, but for x = 0.16, it was almost no changed. These results indicated that the different charge balance compensation mechanism was exist in the samples with x = 0.10 and 0.16. Impedance measurements showed that the resistance tendency exhibited initial decrease and subsequent increase, leading to the electronic and ionic compensation mechanisms with x = 0.10 and 0.16, respectively. Ferroelectric properties also implied charge balance compensation mechanism transition, due to Ps and Pr were higher for x = 0.10 than for x = 0.16, respectively. This work provides a new strategy for modulating the electric properties of BT-based ceramics.