Bi0.5Na0.5TiO3-BaTiO3-CaZrO3:ZnO high-temperature dielectric composites with wide operational range

0.82[0.94Bi0.5Na0.5TiO3-0.06BaTiO3]-0.18CaZrO3:xZnO (BNT-BT-CZ:xZnO, x = 0-0.40 with interval of 0.10) high temperature dielectric composites were prepared and the structural and electrical properties were investigated. Significantly improved temperature-insensitive permittivity spectra have been observed in the composites: the temperature range for low variance in permittivity (Δεr/εr,150 °C < 10%) is 70-190 °C for x = 0, whereas it is extended at least to 30-250 °C for the optimal x = 0.10 at 1 kHz. Especially, for this optimal composite, the variance of permittivity is less than 4.0% in the temperature range of 30-400 °C with the suitable permittivity value of ~ 600 at 10 kHz. By comparatively investigating the properties of unpoled and poled samples, the improved temperature-insensitive permittivity is rationalized by the ZnO-induced local electric field that can suppress the evolution of polar nanoregions and thus enhance the temperature-insensitivity of permittivity.