Phase composition and piezoelectric properties of Pb(Sb_1/2Nb_1/2)–PbTiO₃–PbZrO₃ ceramics

In general, Pb(Sb_1/2Nb_1/2)–PbTiO₃–PbZrO₃ (PSN–PZT) is regarded as a ternary system. However, little information about this system has been reported so far. In this paper, xPb(Sb_1/2Nb_1/2)O₃–(1 − x)Pb(Zr_0.54Ti_0.46)O₃ ceramics were studied systematically by X-ray diffraction, SEM observation and electrical measurements. X-ray diffraction analyses show that PSN is neither perovskite structure nor a single phase structure. PSN–PZT isn’t a ternary system. 6 mol% is the maximum value of PSN to form a single perovskite structure in xPSN–(1 − x)Pb(Zr_0.54Ti_0.46)O₃ ceramics. To alter the Sb/Nb molar ratio, it is found that the solid solubility of Sb³⁺ ion in Pb(Zr_0.54Ti_0.46)O₃ lattice is much smaller than that of Nb⁵⁺ ion and determines the solid solubility of PSN in PZT. For the chemical composition of 0.08PbNbO₃–0.92Pb(Zr_0.54Ti_0.46)O₃, excellent properties of ε _r  = 2078, tanδ = 2.31%, d ₃₃  = 449 pC/N, k _p  = 0.69, Q _m  = 65 and T _C  = 322 °C can be achieved. These properties are superior to that of all compositions with Sb/Nb = 1/1, indicating that the 1/1 ratio of Sb/Nb isn’t the optimal combination for the best electrical properties.