Large strain and temperature-insensitive piezoelectric effect in high-temperature piezoelectric ceramics

Abstract

Here we have, for the first time, reported a giant unipolar strain of ∼0.45% and a temperature-insensitive piezoelectric effect (d₃₃ ∼ 520 pC N⁻¹) in (1 − y)[xBiScO₃–(1 − x)PbTiO₃]–yBi(Zn_1/2Ti_1/2)O₃ (BS–PT–BZT) ceramics with a high Curie temperature of T_C ∼ 425 °C. The morphotropic phase boundary (MPB) of rhombohedral–tetragonal (R–T) phase coexistence can be driven in samples with x = 0.36 and y = 0.01, which is mainly responsible for the enhancement of electrical properties and temperature stability. PFM test results indicate that the addition of BZT can improve the local piezoelectric response of domains, which may lead to the enhancement of piezoelectricity and strain. In addition, ceramics with BZT exhibit good temperature stability of electrical properties. We believe that these materials can be well applied in the field of high-temperature piezoelectric actuators.