Relaxor behavior of piezoelectric Pb(Yb_1/2Nb_1/2)O₃-PbTiO₃ ceramics sintered at low temperature

摘要

A (100-x)Pb(Yb_1/2Nb_1/2)O₃-xPbTiO₃ [PYN-PTx] solid solution system with 49.0 ≤ × ≤ 51.0 was prepared using a conventional ceramics process and sintered at low temperature. When excess PbO was added into the PYN-PTx system, all samples were sintered at temperatures as low as 800°C with good dielectric and piezoelectric properties. It is suggested that a liquid phase with excess PbO was formed during the sintering and improved the densification of PYN-PTx ceramics at low temperatures. For the PYN-PTx binary system, it was found that the temperature dependence of the relative permittivity follows a Curie–Weiss Law above the deviation temperature (T_D) at high temperatures. Good piezoelectric properties of d ₃₃ = 510 pC/N, ε _r = 2800 at RT, k _p = 0.57, and k _t = 0.42 with T_c = 373°C were obtained for PYN-PT49.5 ceramics sintered at 800°C for 8 h.