Enhanced piezoelectric performance of BiScO₃-PbTiO₃ ceramics modified by 0.03Pb(Sb_1/2Nb_1/2)O₃

A series of (0.97-x)BiScO₃-xPbTiO₃-0.03Pb(Sb_1/2Nb_1/2)O₃ (BS-xPT-PSN) piezoelectric ceramics near the morphotropic phase boundary (MPB) for high-temperature actuation application have been devised and synthesized by traditional solid-state reaction method. The phase structure, morphology, dielectric, piezoelectric, and ferroelectric properties have been systematically investigated as a function of PbTiO₃ content. X-ray diffraction (XRD) results revealed that with the content of PbTiO₃ increasing, the phase structure of BS-xPT-PSN ceramics gradually varied from rhombohedral phase toward tetragonal phase. Combined with the dielectric, piezoelectric, and ferroelectric performances, it was clear that MPB of BS-xPT-PSN ceramics located at the region of x = 0.62. The piezoelectric constant d₃₃, electromechanical coupling factor k_p, Curie temperature T_c, remnant polarization P_r of BS-xPT-PSN ceramics with MPB composition were 553 pC/N, 56.7%, 384 °C, and 39.1 μC/cm², respectively, which shows that BS-xPT-PSN ceramics exhibit enhanced piezoelectric performance, and also high T_c. Moreover, the devised BS-xPT-PSN ceramics reduced the consumption of expensive Sc₂O₃ component in pure BS-PT systems. Based on the enhanced piezoelectric performance and decreased cost, it can be deduced that the BS-xPT-PSN ceramics are promising for practical actuator or sensor applications in a relative high temperature environment.