Electromechanical Testing and Modeling of a Pb(Mg _1/3 Nb _2/3 )O ₃ ‐PbTiO ₃ ‐BaTiO ₃ Relaxor Ferroelectric

Abstract

Compressive prestress effects on the electrical and mechanical properties of relaxor ferroelectric materials were studied as a function of temperature for several formulations of Pb(Mg 1/3 Nb 2/3 )O 3 ‐PbTiO 3 ‐BaTiO 3 (PMN‐PT‐BT) ceramics. Experimentally measured polarization and strain, induced by an ac electric field, decreased as compressive stress increased. Effective Young's moduli also were measured under constant dc electric fields. A significant decrease in modulus was observed with increasing field. The prestress and modulus experiments were modeled analytically using a proposed relaxor ferroelectric constitutive law. In general, excellent agreement between the model and experiments was obtained, indicating that the model accurately predicted the coupled behavior of this relaxor ferroelectric material.