Effect of B-site dopants Nb, Ta and W on microstructure and electrical properties of Ca0.85(Li, Ce)0.075Bi4Ti4O15-0.01MnCO3 piezoelectric ceramics

(Li, Ce) and Mn modified CaBi4Ti4O15 (CBT) based ceramics were prepared by the solid state route, and were substituted by the equimolar ions of Nb5+, Ta5+ and W6+ in the B-site. The variations of crystalline structure, microstructure, piezoelectric properties and dielectric properties were investigated. The XRD patterns indicated that all compositions formed a single bismuth layered-structural phase with m = 4. The additions of Nb2O5, Ta2O5 and WO3 into CBT-based ceramics were found to affect the electrical properties and temperature stability of the ceramics. Compared with Ta2O5 and WO3, the Nb-substitued ceramics exhibited the optimum piezoelectric property and dielectric property (d 33 ~ 19.6 pC/N, e r ~ 123.7 and tanδ ~ 0.1 %) among all of these samples, together with a high Curie-temperature (T C ~ 767.6 °C). Thermally activated depolarization behavior also demonstrated that the Nb5+ doped CBT-based ceramics possess outstanding thermal stability of piezoelectric properties. These results indicated that Nb2O5 has a substantial effect on the structure and properties of CBT-based ceramics compared to Ta2O5 and WO3.