Piezoelectric materials for cryogenic and high-temperature applications

Piezoelectric-based sensors/actuators play an important role in structural health monitoring (SHM) of modern aerospace structures. To improve the performance of piezoelectric devices, selection of piezoelectric materials with optimized properties is critical. In this chapter the development of piezoelectric materials used for SHM and the requirements of piezoelectric materials for SHM are introduced. Special attention is focused on the temperature dependence of electromechanical properties and related mechanisms of piezoelectric materials, in particular ferroelectric materials and nonferroelectric piezoelectric materials. Potential piezoelectric materials for cryogenic and ultrahigh temperatures applications are discussed. The uniqueness of relaxor-PbTiO₃ crystals and nonferroelectric piezoelectric crystals are surveyed for possible SHM applications. The chapter concludes with future research on piezoelectric materials.