Ferroelectric Ceramics in the PbMg_1/3Nb_2/3O₃-PbCd_1/3Nb_2/3O₃System

Abstract

Solid solutions (1-x)PbMg1/3Nb2/3O3 + xPbCd1/3Nb2/3O3 with x = 0–0.30 are investigated with purpose to work out a capacitor ceramics with good dielectric properties and low sintering temperature. It is found that the perovskite phase forms at sintering near to 980°C and begins to decompose at higher temperatures. When x grows from 0 to 0.30, the Curie temperature linearly grows from −10°C to +25°C, the dielectric permittivity ϵm in the Curie point TC decreases from 18000 to 6800 and the phase transition becomes more diffused. The dielectric permittivity at room temperature is rather high and the temperature stability is improved. The system is of interest, because it can serve as a base for working out some ceramic materials for capacitors with low sintering temperature, which needs of no special atmosphere at burning. Keywords: ferroelectric ceramicsPbMg1/3Nb2/3O3-PbCd1/3Nb2/3O3 dielectric permittivitylow sintering temperature