Bi 0.5 Na 0.5 TiO 3 -BaTiO 3 -CaZrO 3 :ZnO high-temperature dielectric composites with wide operational range

Abstract 0.82[0.94Bi 0.5 Na 0.5 TiO 3 -0.06BaTiO 3 ]-0.18CaZrO 3 : x ZnO (BNT-BT-CZ: x ZnO, 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 (Δe r /e r,150 °C 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.