Effects of synthesis technique on dielectric properties of CaCu ₃Ti₄O₁₂ ceramic

CaCu₃Ti₄O₁₂ powder was prepared by sol-gel technique, and the CaCu₃Ti₄O₁₂ composites were sintered at 1 000°C for different time after cold pressing with the same pressure and time. The results exhibit that the grain size is affected by the pressure and sintering time. The impedance spectrum measurement results show that both the dielectric constant and dielectric loss have a weak frequency dependence over large frequency region of 50 Hz to 100 kHz, and not only does the dielectric loss decrease but also the dielectric constant remains high sufficiently. The most suitable sintering time is 6 h.