납이 포함되지 않은 압전 특성의 (Na 1/2 Bi 1/2 TiO 3 ) (1-x) -(BaTiO 3 ) x 상전이 거동 연구

Phase Transition Behaviors of Lead-Free Piezoelectric (Na 1/2 Bi 1/2 TiO 3 ) (1-x) -(BaTiO 3 ) x

In this study, the phase transition behaviors of lead-free (Na 1/2 Bi 1/2 TiO 3 ) (1-x) -(BaTiO 3 ) x (NBT-BT) are investigated by using Brillouin spectroscopy. The elastic properties, sound velocity and absorption coefficient of NBT-BT are characterized as a function of temperature along different crystallographic axes. The temperature dependences of the elastic constants of NBT-BT near the morphotropic phase boundary are determined for the first time. The unpoled NBT-BT single crystals exhibits the typical relaxor behaviors, presenting broad acoustic and dielectric anomalies. The application of electric field induced discontinuous changes in the elastic properties at ~110℃, which indicates field-induced phase transition occurred. The electric field also changes the dielectric constant from more relaxor-like to ferroelectric-like dielectric behavior.