Ultralow dielectric loss of BiScO₃-PbTiO₃ ceramics by Bi(Mn_1/2Zr_1/2)O₃ modification

BiScO₃-PbTiO₃ ceramics are attractive for high-temperature piezoelectric applications while their high dielectric loss has to be substantially reduced. In this paper, a ternary perovskite system of xBi(Mn_1/2Zr_1/2)O₃-(1-x-y)BiScO₃-yPbTiO₃ (abbreviated as xBMZ-BS-yPT) with x = 0.02, 0.04 and y = 0.62–0.67 were fabricated by conventional solid-phase method, and their ceramics were systematically studied with regards to phase structure, microstructure, dielectric and piezoelectric properties. X-ray diffraction results indicate a gradual change from rhombohedral to tetragonal phase with increasing PT composition. Morphotropic phase boundary (MPB) is revealed for the system with x = 0.02, y = 0.64, at which ultralow dielectric loss factor (0.58 %), almost unchanged Curie temperature (449 °C), high electromechanical properties (d₃₃ = 360 pC/N, k_p = 0.53), and stable strain output below 200 °C are observed. With such excellent piezoelectric properties and high-temperature stability, BMZ modified BS-PT ceramics are promising candidates for power electromechanical devices, especially operating in high-temperature environments.