Effect of Ba2+ Substitution on Dielectric and Electric-Field-Induced Strain Properties of PMN-PZ-PT Ceramics

Effect of Ba2+ substitution for Pb2+ on the dielectric and electric‐field‐induced strain characteristics of the PMN–PZ–PT ceramics has been investigated in the compositions of the tetragonal‐rich 0.2PMN–0.36PZ–0.44PT and rhombohedral‐rich 0.2PMN–0.4PZ–0.4PT ceramics. The phase approached cubic structure from the tetragonal and rhombohedral, and grain size was reduced when the Ba2+ cation was substituted. As Ba2+ content increased, frequency‐dependent relaxor‐like behavior of the dielectric constant was observed at temperatures below the dielectric maximum (Tmax) for compositions with 20 and 25 mol% Ba2+. Electric‐field‐induced strain was maximized in the 12 mol% Ba2+‐substituted 0.2PMN–0.4PZ–0.4PT specimen (Smax= 0.15%), and maximum piezoelectric, d31, was 300 in the 14 mol% Ba2+‐substituted 0.2PMN–0.4PZ–0.4PT specimen.