Effect of thickness on the dielectric property and nonlinear current-voltage behavior of CaCu3Ti4O12 thin films

Dielectric properties and leakage current behavior in CaCu3Ti4O12 (CCTO) films with different thickness are studied. It is found that the permittivity is affected simultaneously by the electrode interface and the microstructure of the film. The influence of the interfacial layer reduces and the ac electric process transfers from grain boundary to bulk conductivity relaxation with the film thickness increasing. The Poole-Frenkel emission is dominated in thicker CCTO film. Interface-related conductive process coexists with the bulk-limited process in thinner film.