Enhanced electrical properties of novel Pb(Ni_1/3Nb _2/3)O₃-BiScO₃-PbTiO₃ ternary system ear morphotropic phase boundary

A novel xPb(Ni_1/3Nb_2/3)O₃-(1-x)(0. 30BiScO₃-0.70PbTiO₃) (PNN-BS-PT) ternary system was prepared by the columbite precursor method. he phase structure, microstructure, and electrical properties of ceramics of this system were investigated to identify the morphotropic phase boundary (MPB) composition of this system. The MPB with coexisting rhombohedral-tetragonal phases of PNN-BS-PT was located at pproximately x = 0:35, confirmed by their respective electric properties. With increasing PNN content, the coercive field EC, the Curie emperature TC, and the rhombohedral-to-tetragonal phase transition temperature T_R-T were found to decrease and showed nearly linear ependences on their compositions. The enhanced properties were achieved in the MPB composition with x = 0:35, which are as follows:dielectric constant εr = 3160 (1 kHz), piezoelectric coefficient d₃₃ = 490 pC/N, and electromechanical coupling factor k_p = 0:44. In addition, a large ipolar strain on the order of 0.6% was achieved for the composition when an electrical field E = 40 kV/cm was applied.