Synthesis and electrical properties of (1−x)(Na_0.5Bi_0.5)TiO₃−xBa(Mg_0.5W_0.5)O₃ piezoelectric ceramics

(1−x)(Na0.5Bi0.5)TiO3−xBa(Mg0.5W0.5)O3 particles with x = 0.00–0.08 were synthesized by a solvothermal approach at 230 °C for 48 h. The results of X-ray diffraction analysis revealed a rhombohedral–tetragonal morphotropic phase boundary (MPB) composition existed in the range of x = 0.05–0.06 at room temperature. The ceramics around the phase boundary composition provide excellent piezoelectric properties, i.e., the highest piezoelectric constant, d33, (108 pC/N) could be realized at x value of 0.05. By using a casting sintering method, the ceramics consisted of the oriented rod-like particles with condensed sintering body were obtained, and the piezoelectric properties could be improved to show such a high piezoelectric constant as d33 = 112 pC/N at x value of 0.05.