Non-Ohmic and dielectric properties of CaCu3Ti4O12-MgO nanocomposites

► Addition of 5 vol.% MgO can improve dielectric and nonlinear properties of CCTO. ► The low-frequency tan δ of CCTO-MgO (5 vol.%) was greatly reduced. ► ε′ of CCTO-MgO (5 vol.%) is higher than 104 in the frequency range of 102-105 Hz. ► Addition of 5 vol.% MgO can enhance breakdown voltage and nonlinear coefficient.