Electrical performance and ferroelectric phase transition characteristic in different oriented 0.73PMN‐0.27PT single crystals

Abstract

The electrical and optical properties of (001)-and (110)-oriented 0.73 Pb(Mg 1/3 Nb 2/3 )O 3 -0.27PbTiO 3 single crystals are systematically investigated at various temperatures, both of which present a series of ferroelectric phase transition processes. Dielectric performance measurements reveal that the ferroelectric phase transition occurs over a temperature range, rather than at one temperature point. By testing the ferroelectric hysteresis P-E curves as well as bipolar and unipolar electric field-induced strain S-E curves, the values of remnant polarization, coercive field, maximum strain, and converse piezoelectric constant d 33 * change considerably near the phase transition temperatures. Simultaneously, the 0.73PMN-0.27PT single crystals with (001)-and (110)-orientations under a low electric field show ultrahigh d 33 * values of 3540 and 2817 pm/V, respectively, which can be attributed to the electric field-induced monoclinic and orthorhombic phases, respectively. The series of ferroelectric phase transitions upon heating, that is, from rhombohedral ferroelectric to monoclinic/orthorhombic, followed by from monoclinic/orthorhombic to tetragonal, and finally from tetragonal to cubic paraelectric, are further investigated via polarized light microscopy and Raman spectroscopy.