Enhanced resistance in Bi(Fe1-xScx)O3-0.3BaTiO3 lead-free piezoelectric ceramics: Facile analysis and reduction of oxygen vacancy

Abstract

We reported a facile analysis and reduction of oxygen vacancy (VO••) in 0.7Bi(Fe1-xScx)O3-0.3BaTiO3 (0≤x≤0.08) ceramics. The leakage current mechanism was investigated intensively. Our results indicated that oxygen vacancies are the main cause for the high conductivity in BF-BT ceramics, and their concentration was quantitatively estimated from the Bi3+ content and the average oxidation state of iron. The VO•• concentration was effectively suppressed and the insulation resistance was enhanced by almost two orders of magnitude after doping 2%mol Sc3+. The enhanced insulation resistance contributed to excellent piezoelectric properties with d33 = 165 pC/N, TC = 505 °C, and kp = 26%. The proposed analysis method used to quantify the VO•• concentration provides valuable indications to reduce the leakage current density and improve the piezoelectric properties of BF-BT based ceramic.