Giant dielectric constant in CaCu3Ti4O12 nanoceramics

Abstract

Nanoceramics of CaCu3Ti4O12 (CCTO) were synthesized by mechanosynthesis and spark plasma sintering with grain size of 150–200 nm. Giant dielectric constant properties are observed in the CCTO nanoceramics due to internal barrier layer capacitance (IBLC) effects. Impedance spectroscopy data suggest that the presence of resistive grain boundaries in addition to resistive domain boundaries is the origin of the IBLCs in CCTO nanoceramics.