CaCu3Ti4O12 ceramics from different methods: microstructure and dielectric

CaCu3Ti4O12 (CCTO) ceramics were synthesized by methods of sol–gel, traditional solid-state reaction, and thermal decomposition of organic solution. The results exhibit that the microstructures and electric characteristics are affected by the methods of synthesis. The X-ray diffraction patterns show that all samples have a perovskite-like CCTO phase. Moreover, CCTO ceramic from traditional solid-state reaction have the phases of TiO2 and CuO. The scanning electron microscopy images show that CCTO ceramics from different methods have different grain sizes, grain boundaries, and densities. Dielectric properties of the CCTO ceramics were characterized in a broad frequency range (10–107 Hz) at room temperature. The CCTO ceramics from thermal decomposition of organic solution have the dielectric constant of more than 5 × 104 at 10 Hz. The nonlinear relationship between the current density and the electric field strength can be observed in all the three samples.