Structure, dielectric, and piezoelectric properties of (0.97-x)BiScO3-xPbTiO3-0.03Pb(Mn1/3Nb2/3)O3 high temperature and high power piezoelectric ceramics

(0.97-x)BiScO₃-xPbTiO₃-0.03Pb(Mn_1/3Nb_2/3)O₃ (BS-PT-PMN) (x=0.54, 0.56, 0.58, 0.59, 0.60, and 0.62) ceramics were prepared by traditional solid state reaction method. The high Curie temperature T_c, large piezoelectric constant d₃₃ and high mechanical factor Q_m were obtained in the ternary solid solutions at the same time. X-ray diffraction analysis revealed that the morphotropic phase boundary (MPB) separating rhombohedral and tetragonal phase was found at x= 0.58. Values of the dielectric constant ε_r dielectric loss tanθ at 1kHz, Curie temperature T_c, piezoelectric constant d₃₃ and for the composition x=0.58 were of 710, 0.015, 437°C, 300 C/N and 200, respectively. Temperature-dependent electromechanical coupling coefficient were stable from room temperature up to 400°C, about 250°C higher than that of conventional Pb(Zr, Ti)O₃ (PZT) piezoelectric ceramics. These results indicated BS-PT-PMN ceramics could be promising candidates for high temperature and high power piezoelectric applications.