Polarized Raman study on phase transitions in 0.24Pb(In_1/2Nb_1/2)O₃-0.43Pb(Mg_1/3Nb_2/3)O₃-0.33PbTiO₃ single crystal

Polarized Raman spectroscopy was performed to investigate the local lattice structure and phase transitions of unpoled 0.24Pb(In_1/2Nb_1/2)O₃-0.43Pb(Mg_1/3Nb_2/3)O₃-0.33PbTiO₃ (0.24PIN-0.43PMN-0.33PT) single crystal in the temperature range from 30 °C to 260 °C. M_A- and M_C-type monoclinic phases were detected by micro-Raman spectra measured in different micro areas. Temperature dependence of Raman intensities, frequency shifts, mode merge and intensity ratios in the VV and VH geometries were investigated. Our results indicated that the monoclinic-tetragonal (M-T) phase transition of the ternary relaxorbased ferroelectric single crystal 0.24PIN-0.43PMN-0.33PT occurs at 85 °C, which is verified by the mode merging from 520 cm^-1 and 580 cm^-1 to 500 cm^-1, and the tetragonal-cubic (T-C) phase transition happens at 200 °C based on the vanishing mode at 780 cm^-1 measured in the VH polarization.