Study of temperature-dependent Raman spectroscopy and electrical properties in [001]-oriented 0.35Pb(In1/2Nb1/2)O3-0.35Pb(Mg1/3Nb2/3) O3-0.30PbTiO3-Mn single crystals.

In this work, the temperature-dependent Raman spectra and electrical properties of the [001]-oriented 0.5mol.% Mn-doped 0.35Pb(In_1/2Nb_1/2)O₃-0.35Pb(Mg_1/3Nb_2/3)O₃-0.30PbTiO₃-Mn (PIMNT-Mn) single crystals were investigated. All the unpoled and poled PIMNT-Mn single crystals experience a ferroelectric tetragonal phase to paraelectric cubic phase transition (FE_T-P_C) around 183 °C (T_C), which exhibits a second-order transition behavior. Whereas, the poled PIMNT-Mn single crystals exhibit another two dielectric anomalies around 130 °C (T_RM) and 148 °C (T_MT), in which the ferroelectric rhombohedral phase to ferroelectric monoclinic phase (FE_R-FE_M) and the ferroelectric monoclinic phase to ferroelectric tetragonal phase (FE_M-FE_T) transitions take place, respectively. Both the two ferroelectric phase transitions exhibit a first-order transition behavior. The discontinuous change of the phase degree (h) and frequencies (f_r and f_a) around T_RM suggest the occurrence of the FE_R-FE_M phase transition in the poled PIMNT-Mn single crystals. The narrowing of the 510 cm^–1 and 582 cm^–1 Raman modes around the T_RM, T_MT, and T_C temperatures shown in the temperaturedependent Raman spectra suggests their increased ordering of the local structure. The intensity ratio of I_{272 cm–1}/I_{801 cm–1} increases obviously around the phase transition temperatures (T_RM, T_MT, and T_C), indicating the reduction of the long-range order. The anomalous broadening of the 272 cm^–1 Raman mode around the T_RM, T_MT, and T_C temperatures indicates the occurrence of the successive ferroelectric phase transitions (FE_R-FE_M, FE_M-FE_T, and FE_T-P_C) with increasing temperature in the poled PIMNT-Mn single crystals. [ABSTRACT FROM AUTHOR]