Effect of Sn content on structure and properties near the morphotropic phase boundary in a PbSnO₃-PbZrO₃-PbTiO₃ ternary system

Piezoelectric ceramics in the PbSnO₃-PbZrO₃- PbTiO₃ (PZST) ternary system with pure perovskite structure were synthesized by a conventional solid state reaction method with the compositions near the morphotropic phase boundary (MPB). The influences of Sn content on dielectric, piezoelectric, and ferroelectric properties of Pb(Zr _x Sn _y Ti_1-x-y )O₃ ceramics were investigated. The experimental results showed that, with increasing the Sn content along the Ti = 0.48 line, the optimized sintering temperature, tetragonality, and Curie temperature (T _C) decreased monotonically. The polarization-electric field hysteresis loops show a pinning effect in some low Sn compositions. Frequency dependence of the pinning effect was studied accompanied with current-electric field curve analysis. The PZST compositions near MPB show promising advantages for practical applications.