Coexistence of relaxor and normal ferroelectric phases in morphotropic phase boundary compositions of lanthanum-modified lead zirconate titanate

Hot-stage transmission electron microscopy studies of lanthanum-modified lead zirconate titanate (Pb1-xLax-(Zr0.53Ti0.47)(1-x/4)O-3 (PLZT 100x/53/47) have been performed for compositions close to the morphotropic phase boundary (MPB). These studies have revealed the coexistence of relaxer and normal ferroelectric phases, Lanthanum substitution disrupts long-range ferroelectric order, resulting in short-range polar ordering, Investigations also have been performed using dielectric spectroscopy, electrically induced polarization, and strain methods, Three phases have been found for 10/53/47: a low-temperature tetragonal phase, a high-temperature cubic phase, and an intermediate-temperature pseudocubic phase that exhibits relaxer ferroelectric behavior, Induced strain studies of 10/53/47 show a gradual change from butterfly-shaped to slim-quadratic loops with increasing temperature, In addition, the remanent strain decreases with increasing temperature, and reversible strain shows a peak at 80 degrees C that corresponds to the appearance of intermediate phase.