Preparation and Characterization of High Temperature Perovskite Ferroelectrics in the Solid-Solution (1-<i>x</i>)BiScO₃–<i>x</i>PbTiO₃

TLDR

The (1‑x)BiScO₃–xPbTiO₃ system belongs to a new class of high‑temperature piezoelectrics based on Bi(Me)O₃–PbTiO₃ with large trivalent cations such as Sc, Y, Yb, and In. The study investigates the dielectric and piezoelectric properties of the (1‑x)BiScO₃–xPbTiO₃ solid solution. Perovskite stability was achieved for x > 50 mol % PbTiO₃, with a rhombohedral phase that transforms to tetragonal near x = 64 mol % PbTiO₃ at the morphotropic phase boundary. Compositions near the MPB show enhanced dielectric and piezoelectric behavior, with d₃₃ up to 450 pC/N—comparable to soft PZT at 450 °C and over 100 °C higher than commercial PZT—making the material suitable for high‑temperature, temperature‑stable actuators and transducers.

Abstract

The dielectric and piezoelectric properties of the new perovskite solid solution system (1-x)BiScO3–xPbTiO3 were investigated. This system is representative of a new group of high temperature piezoelectrics that includes Bi(Me)O3–PbTiO3, where Me+3 is a relatively large cation, Sc, Y, Yb, In, etc., and combinations thereof. In the (1-x)BiScO3–xPbTiO3 series, perovskite stability was achieved for x>50 mol% PbTiO3 being ferroelectric rhombohedral and transforming to ferroelectric tetragonal in the region x=64 mol% PbTiO3, designated as the morphotropic phase boundary (MPB). Analogous to (1-x)PbZrO3–xPbTiO3 (PZT), the dielectric and piezoelectric properties were enhanced for compositions near the MPB. Piezoelectric coefficient d33 values reached 450 pC/N, comparable to soft PZT's with a transition temperature of 450°C, more than 100°C higher than commercial PZT. The combination of high TC and excellent piezoelectric activity make (1-x)BiScO3–xPbTiO3 materials candidates for high temperature, and temperature stable actuators and transducers.