Structural evolution of a high-temperature piezoelectric Pb(In1/2Nb1/2)O3–PbTiO3 ceramic under an in situ electric field

Abstract

Pb(In_1/2Nb_1/2)O₃–PbTiO₃ (PIN–PT) is a typical perovskite-type relaxor ferroelectric system with a high Curie temperature (T_C) and is widely utilized as an end-member in constructing high-performance piezoelectric systems. In this work, we conducted an in situ electric field (E) structural investigation of 0.64PIN–0.36PT, which demonstrates an optimal piezoelectric coefficient d₃₃ of 322 pC N⁻¹ and high T_m of 312 °C. It is found that monoclinic (M) and tetragonal (T) phases coexist in 0.64PIN–0.36PT, and that there is a reversible change in the phase fraction induced by E. Structural refinement using diffraction data under bipolar E reveals that the lattice parameters and unit-cell volume of the M phase undergo a greater change in comparison to the T phase. The reversible phase transformation and the relatively flexible M structure render the material capable of large lattice strains and domain switching, and are responsible for the enhanced piezoelectric properties of PIN–PT at the morphotropic phase boundary. These findings offer a detailed structural description of the high-temperature piezoelectric PIN–PT end-member, which will serve as the foundation for developing high-performance piezoelectric systems.