Ultrahigh temperature Bi₃Ti_0.96Sc _0.02Ta_0.02NbO₉-based piezoelectric ceramics

The effect of (Sc,Ta,Ce) doping on the properties of Bi3 TiNbO9 (BTNO)-based ceramics was investigated. The cerium modification greatly improves the piezoelectric activity of Bi₃(Ti_0.96Sc _0.02Ta_0.02)NbO₉-based ceramics and significantly decreases the dielectric dissipation. The d₃₃ of Bi₃Ti_0.96Sc_0.02Ta_0.02NbO ₉ +x wt % CeO₂ (x=0.35) was found to be 18 pC/N, the highest value among the BTNO-based ceramics and almost three times as much as the reported d₃₃ values of the pure BTNO ceramics (∼6 pC/N). The modification increased the resistivity ρ of the samples extremely, resolving the low resistivity problem for high temperature applications. The dielectric spectroscopy shows that the T_C for all the ceramics is higher than 900°C. The mechanical quality factor Q and planar coupling factors k _p and k_t of Bi₃Ti_0.96Sc _0.02Ta_0.02NbO₉ +0.35 wt % CeO₂ ceramic were found to be 2835, 9%, and 23%, respectively, and it has high T _C and stable piezoelectric properties, demonstrating that the (Sc,Ta,Ce) modified BTNO-based material is a wonderful candidate for high temperature applications.