Polarized Raman study on phase transitions in 0.24Pb(In_(1/2)Nb_(1/2))O_3-0.43Pb(Mg_(1/3)Nb_(2/3))O_3-0.33PbTiO_3 single crystal

摘要

Polarized Raman spectroscopy was performed to investigate the local lattice structure and phase transitions of unpoled 0.24Pb(In_(1/2)Nb_(1/2))O_3-0.43Pb(Mg_(1/3)Nb_(2/3))O_3--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 W and VH geometries were investigated. Our results indicated that the monoclinic-tetragonal (M-T) phase transition of the ternary relaxor-based 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.