Morphotropic phase boundary in high temperature ferroelectric xBi(Zn1/2Ti1/2)O3 − yPbZrO3 − zPbTiO3 perovskite ternary solid solution

A bismuth and lead oxide based perovskite ternary solid solution xBi(Zn1/2Ti1/2)O3 − yPbZrO3 − zPbTiO3 (xBZT − yPZ − zPT) was investigated as an attempt to develop a high TC ferroelectric material for piezoelectric sensor and actuator applications. A morphotropic phase boundary (MPB) between rhombohedral and tetragonal phases was determined through an XRD study on a pseudobinary line 0.1BZT − 0.9[xPT − (1 − x)PZ] for composition 0.1Bi(Zn1/2Ti1/2)O3 − 0.5PbZrO3 − 0.4PbTiO3. Enhanced piezoelectric and ferroelectric activities were observed for MPB composition with dielectric constant εr′ ~ 23,000 at Curie temperature (TC) ≈ 320 °C, remanent polarization (Pr) = 35 μC/cm2, piezoelectric coefficient (d33) = 300 pC/N, unipolar strain = 0.15%, and electromechanical coupling coefficient (kP) = 0.45.