High rhombohedral to tetragonal phase transition temperature and electromechanical response in Pb(Yb1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3-PbTiO3 ferroelectric system near the morphotropic phase boundary

Abstract

Relaxor-PT crystals, that is, Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) and Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT), have been used in mechanical to electric energy translation devices, such as for high-frequency imaging and underwater detection. However, low temperature usage remains a problem for high temperature applications, which are restricted by rhombohedral to tetragonal phase temperatures (TR-T). In this work, we synthesized a new xPb(Yb1/2Nb1/2)O3-yPb(Sc1/2Nb1/2)O3-0.37PbTiO3 (x = 0.2˜0.45) (xPYN-yPSN-0.37 P T) ternary piezoelectric polycrystalline with high TR-T = 225˜245 °C. For 0.45PYN-0.18PSN-0.37 P T ceramics, the piezoelectric coefficient d33, mechanical coupling factors k33, kp, and kt, and dielectric coefficients εr and TR-T are on the order of 330 pm/V, 68.3%, 54.3%, 49.3%, 930, and 245 °C, respectively. Thermal piezoelectric and ferroelectric behaviors were investigated in 0.45PYN-0.18PSN-0.37 P T polycrystalline, which are good candidates for high temperature piezoelectric application. DSC curves for xPYN-yPSN-0.37 P T systems present two peaks at 1213 and 1291 °C during the cooling process, showing good crystallization behavior and suitability for single crystal growth.