Orientation and phase transition dependence of the electrocaloric effect in 0.71 PbMg_(1/3)Nb_(2/3)O_3-0.29PbTiO_3 single crystal

摘要

In this letter, the electrocaloric effect (ECE) of <111>- and <001>-oriented 0.71 PbMg_(1/3)Nb_(2/3)O_3-0.29PbTiO_3 (0.71PMN-0.29PT) single crystals is investigated with emphasis on the effects of phase transitions and their dependence on electric field. We show that crystal orientation and more specifically the complex phase transitions taking place in the specific composition above have large effects on the maximum ECE temperature, △T_(max), its peak temperature, T_(EC), and the width of the ECE peak of the AT(T) curve. The investigation shows that ECE may be tuned by a proper choice of 0.71PMN-0.29PT crystal orientations.x