B-site doping effect on electrical properties of Bi4Ti3−2xNbxTaxO12 ceramics

B-site vacancies Bi4Ti3−2xNbxTaxO12 (BTNT) ceramics were prepared and the influence of the Nb2O5/Ta2O5 additive on the structure and electrical properties of the ceramics was investigated. The results showed thermal variations of permittivity and dielectric loss with a diffuse phase transformation. The Nb/Ta co-doping at the B-site could induce the distortion of oxygen octahedral and reduce the oxygen vacancy concentration by a compensating effect. The piezoelectric coefficient of Bi4Ti2.98Nb0.01Ta0.01O12 ceramics with an elaborate composition is found to be 26 pC N−1.