Investigation of ternary system Pb(Sn,Ti)O3–Pb(Mg1/3Nb2/3)O3 with morphotropic phase boundary compositions

(1 − x)Pb(Sn1−yTiy)O3–xPb(Mg1/3Nb2/3)O3 (x = 0.1–0.4, y = 0.45–0.65) ternary system was prepared using two-step columbite precursor method. Phase structure of the synthesized ceramics was studied by using X-ray powder diffraction and the morphotropic phase boundary (MPB) curve of the ternary system was confirmed. The isothermal map of Curie temperature (TC) in the phase diagram was obtained based on the dielectric–temperature measurements. The coercive field EC and internal bias field Ei were found to increase with increasing PT content, while decrease with increasing PMN content. The optimum properties were achieved in the MPB composition 0.8Pb(Sn0.45Ti0.55)O3–0.2Pb(Mg1/3Nb2/3)O3, with dielectric permittivity ɛr, piezoelectric coefficient d33, planar electromechanical coupling kp, mechanical quality factor Qm and TC of being on the order of 3040, 530pC/N, 55.5%, 320 and 190 °C, respectively, exhibiting potential usage for high power application.