Synthesis, characterization and giant dielectric properties of CaCu3Ti4O12 ceramics prepared by a polyvinyl pyrrolidone-dimethylformamide solution route

Abstract

CaCu3Ti4O12 powders were successfully prepared by a polyvinyl pyrrolidone-dimethylformamide solution route. Pure phase of CaCu3Ti4O12 was achieved at a low calcination temperature and short reaction time at 800 °C for 3 h. High porosity and neck-grain growth network were observed in CaCu3Ti4O12 powders. The sintered CaCu3Ti4O12 ceramic with fine-grained microstructure exhibited a very high dielectric constant of 1.26 × 104 and low loss tangent of about 0.07 at 1 kHz and 20 °C. Nonlinear current-voltage behavior and dielectric properties were found to be closely related to the microstructure.