Dielectric properties and relaxor behavior of (1-x)Ba(Zr0.15Ti0.85)O3 - xBa(Mg(1⁄3)Nb(2⁄3))O3 ceramics for capacitor applications

Abstract

The Ba(Zr0.15Ti0.85)O3 (BZT) ceramics were fabricated by the conventional solid-state method and the impact of Ba(Mg(1/3) Nb(2/3))O3 (BMN) addition into the BZT matrix on their microstructure, dielectric and ferroelectric properties were examined. According to the XRD analysis, the (1-x)Ba(Zr0.15Ti0.85)O3-xBa(Mg(1⁄3)Nb(2⁄3))O3 ceramics retain a pseudo-cubic ABO3 perovskite structure with an apparent decrease in c/a ratio as x increases. The SEM images show that the BZT-BMN ceramics instigate the reduction of the average grain sizes. And as the BMN content increases to 0.01, the Mg2+ and Nb5+ ion substitutions in the B-sites greatly improved the dielectric constant of BZT ceramics at room temperature. The frequency dispersion of the dielectric constant and the diffuseness of phase transition for BZT-BMN ceramics are enhanced by increasing the BMN addition. In the modified BZT ceramics, the dielectric maximum temperature (Tm) is reduced as the BMN content increases, and the temperature stability of the permittivity is modified by BMN addition. The hysteresis loop grows thinner and the remnant polarization, as well as coercive field, is greatly reduced as the BMN addition increases.