Tuning electrical heterogeneity in CaCu3Ti4O12-ZnO ceramics for high dielectric and nonlinear properties

Abstract

Tuning the electrical heterogeneity of CaCu3Ti4O12 (CCTO) ceramic is extremely important to improve its properties. In this work, the CCTO ceramics with enhanced dielectric and nonlinear properties were obtained by the introduction of nano ZnO based on the electrical heterogeneity modulation strategy. As a result, all the CCTO-ZnO samples show the colossal dielectric constant of 104–105 at room temperature. Meanwhile, the dielectric constant of CCTO-ZnO samples exhibits better stability in a wide frequency range from 101 Hz to 105 Hz and over a temperature scope of 30–210 °C. Most importantly, the x = 0.04 sample presents a relatively lower room-temperature dielectric loss of about 0.07 at 103 Hz. Furthermore, the breakdown field strength accompanied by the nonlinear coefficient of CCTO-ZnO ceramics is also improved. The enhancement of dielectric and nonlinear behaviors in these ceramics is mainly ascribed to the tunable electrical heterogeneity as per the internal barrier layer capacitor (IBLC) model.