High performance ferroelectric relaxor-PbTiO3 single crystals: Status and perspective

TLDR

Ferroelectric materials, particularly relaxor‑PbTiO₃ single crystals, are essential in ultrasonic transducers, sensors, and actuators because of their ultrahigh piezoelectric and electromechanical properties. This article offers a perspective on the current status and future development of relaxor‑PbTiO₃ crystals. The authors review Bridgman growth of crystals up to 100 mm in diameter and 200 mm in length, survey dielectric and electromechanical characterizations, discuss boundary conditions and the physical origins of high piezoelectricity, and compare applications to conventional ceramics.

Abstract

Ferroelectrics are essential components in a wide range of applications, including ultrasonic transducers, sensors, and actuators. In the single crystal form, relaxor-PbTiO3 (PT) piezoelectric materials have been extensively studied due to their ultrahigh piezoelectric and electromechanical properties. In this article, a perspective and future development of relaxor-PT crystals are given. Initially, various techniques for the growth of relaxor-PT crystals are reviewed, with crystals up to 100 mm in diameter and 200 mm in length being readily achievable using the Bridgman technique. Second, the characterizations of dielectric and electromechanical properties are surveyed. Boundary conditions, including temperature, electric field, and stress, are discussed in relation to device limitations. Third, the physical origins of the high piezoelectric properties and unique loss characteristics in relaxor-PT crystals are discussed with respect to their crystal structure, phase, engineered domain configuration, macrosymmetry, and domain size. Finally, relaxor-PT single crystals are reviewed with respect to specific applications and contrasted to conventional piezoelectric ceramics.