Abstract:The microstructure, dielectric and ferroelectric properties of (1-y)Ba(Zr_0.1Ti_0.9)O₃-yBa(Zn_1/3Nb_2/3)O₃ (y=0-0.05) ceramics prepared by traditional solid state method were investigated by X-ray diffractometer, scanning electron microscope, electric parameter testing system and ferroelectric tester. It is found that the barium zirconate titanate based ceramics are single-phase perovskites as y increases up to 0.05 and their average grain size decreases with the increase of y. The permittivity maximum ε_r,max is suppressed from 8948 to 1611 at 1 kHz with increasing y, and the ferroelectric-paraelectric phase transition temperature T_m decreases from 93 to -89 °C at 1 kHz as y increases. The composition-induced diffuse phase transition is enhanced with increasing y. The relaxor-like ferroelectric behavior with a strong frequency dispersion of T_m and permittivity at T<T_m accompanied by a strong diffuse phase transition is found for the system with high y value. The remnant polarization decreases with increasing y, while the coercive field decreases remarkably and then increases with the increase of y.

Key words: barium zirconate titanate; dielectric properties; relaxor ferroelectric behavior; perovskite; phase transition