Large, thermally stabilized and fatigue-resistant piezoelectric strain response in textured relaxor-PbTiO3 ferroelectric ceramics

Abstract

Piezoceramics with both high strain response and excellent output stability are highly in demand for electronic actuator applications. Unfortunately, enhanced strains are generally accompanied by temperature and e-field instabilities for relaxor-PbTiO₃ ferroelectrics near the curved morphotropic phase boundary (MPB). In this work, we report the simultaneous achievements of substantially enhanced piezoelectric strain (d₃₃* ∼ 990 pm V⁻¹), greatly improved temperature stability (strain variation below 10% over 25–150 °C) and excellent fatigue resistance (almost no strain variation at a bipolar e-field of 30 kV cm⁻¹ up to 10⁵ cycles) in a relaxor-PbTiO₃ ferroelectric ceramic with controlled grain orientation along [001]_c, based on integrating texture engineering and composite effect strategies. The temperature–insensitive strain response can be mainly attributed to the thermally stabilized ε_r × P (dielectric permittivity × polarization) and stable domain response over a broad temperature range, which suppressed the adverse effect (strain variation ∼60% over 25–150 °C in the non-textured counterpart) caused by the intermediate ferroelectric phase transition. Besides, the inherent anisotropy properties and enhanced domain mobility in the textured ceramics further contribute to the substantially improved fatigue endurance. This work paves the way for exploring large and stable strain response in ferroelectrics with strongly curved MPB, and can also largely broaden application areas of relaxor-PbTiO₃ ceramics to high-performance, stable and robust actuators.