Dielectric behavior and phase transition in 111-oriented PIN–PMN–PT single crystals under dc bias

摘要

Temperature and electric field dependences of the dielectric behavior and phase transition for[111]-oriented 0.23PIN–0.52PMN–0.25PT(PIN-PMN–0.25PT)and 0.24PIN–0.43PMN–0.33PT(PIN–PMN–0.33PT)single crystals were investigated over a temperature range from
100℃ to 250℃ using field-heating(FH)dielectric measurements.The transition phenomenon from ferroelectric microdomain to macrodomain was found in rhombohedra(R)phase region in the single crystals under dc bias.This transition temperature T_(f) of micro-to-macrodomain is sensitive to dc bias and move quickly to lower temperature with increasing dc bias.The phase transition temperatures in the two single crystals shift toward high temperature and the dielectric permittivities at the phase transition temperature decrease with increasing dc bias.Especially,the phase transition peaks are gradually broad in PIN–PMN–0.33PT single crystal with the increasing dc bias.Effects of dc bias on the dielectric behavior and phase transition in PIN–PMN–PT single crystals are discussed.