Effect of Cd Dopant on Dielectric Properties of CaCu₃Ti₄O₁₂

Abstract

  The doping effect of Cd ions on the giant dielectric response in Ca_1−xCd_xCu₃Ti₄O₁₂ ceramics with x=0, 0.01, 0.03, 0.05 and 0.1 was studied in the frequency range of 10 kHz–1 MHz over the temperature range of 300–850 K. It is found that the chemical substitution of Cd ions at the Ca sites results in decrease in dielectric constant by 9% – 55% for Cd-doped CaCu₃Ti₄O₁₂, at room temperature. Although the decrease in the dielectric constant was observed by Cd doping, no drastic suppression of dielectric response could be observed by Cd-doping. The dielectric anomaly was found at T₁ (727 K for x=0.05), which suggests a phase transition. This T₁ decreases linearly with increasing x. CdCu₃Ti₄O₁₂ is still a member of high-dielectric materials.