Effect of sintering temperature and Cu-rich secondary phase on dielectric properties of microwave processed CaCu3Ti4O12 ceramics

Effect of sintering at different temperature on dielectric properties of microwave processed CaCu3Ti4O12 (CCTO) ceramics have been investigated over the frequency range from 100 Hz to 1 MHz at room temperature. Density (ρ) as well as dielectric constant (ϵr) increased with the sintering temperature up to 1050°C, beyond that “ρ” and ‘ϵr’ both decreased. At 1 KHz, maximum value of dielectric constant (ϵr) achieved ∼13,000 with a loss (D) ∼ 0.1. Very weak temperature dependence was found in dielectric constant bellow 150°C. Change in dielectric constant can be explained on the basis of IBLC model in presence of secondary CuO phase.