Ferroelectric Sb-doped PMN-PT crystal: high electromechanical response with true-remanent polarization and resistive leakage analyses

In this work, pure and Sb-doped PMN-PT (64:36) crystals with pure perovskite phase have been successfully grown using high temperature solutions technique (or, flux technique), in the vicinity of MPB with the size of the crystals varying from 2 × 2 × 1 mm³ to 7 × 5 × 4 mm³. Various properties like dielectric, piezoelectric, ferroelectric and pyroelectric were investigated for the Sb-doped PMN-PT crystals and have been compared to that of pure PMN-PT crystals. In the dielectric studies, the Curie temperature (T_c) for the pure and doped crystal was found to be 190 °C and 155 °C, respectively. Butterfly loops were traced from which a high value of the piezoelectric coefficient for Sb-doped crystal (d₃₃* = 1972 pm/V) was revealed in the voltage range 250–500 V which was fairly greater than that observed for pure PMN-PT crystal (d₃₃* = 1413 pm/V). The Sb-doped PMN-PT crystals displayed excellent saturated ferroelectric hysteresis loops with higher remanent polarization (P_r) value compared to the pure PMN-PT crystals. The doped crystals also displayed good fatigue resistant characteristic indicating the high ferroelectric quality of the crystals. The true or usable polarization (P_tr) component was extracted using the “True-remanent hysteresis” task. The value of P_tr was found to be 41.53 µC/cm² suggesting lesser contributions (~ 7%) from non-remanent (non-switchable) components of polarization further confirming the good ferroelectric quality of the Sb-PMN-PT crystals. Also, the resistive-leakage characteristic of the doped crystal was analyzed using Time-dependent compensated hysteresis task. These results demonstrate that the Sb-doped PMN-PT crystal possesses excellent properties to achieve a variety of applications.