Effects of synthesis technique on dielectric properties of CaCu₃Ti₄O₁₂ ceramic

A. RAJABTABAR-DARVISHI¹, LI Wei-li¹, O. SHEIKHNEJAD-BISHE², WANG Li-dong¹, LI Xiao-liang¹, LI Na¹, FEI Wei-dong^{1, 3}

(1. State Key Laboratory of Advanced Welding and Joining,
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001, China;
3. School of Mechanical Engineering, Qinghai University, Xi’ning 810016, China)

Abstract: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.

Key words:CaCu₃Ti₄O₁₂ ceramics; dielectric constant; dielectric loss; sintering time