Sol–gel synthesized pure CaCu3Ti4O12 with very low dielectric loss and high dielectric constant

Abstract

CaCu3Ti4O12 ceramics were synthesized by the sol–gel method. The microstructural and dielectric properties were investigated. X-ray powder diffraction analysis indicated that no second phase occurred. The dielectric properties were investigated in the frequency range between 20Hz and 2MHz, and the dielectric constants (ε′) of CaCu3Ti4O12 ceramic samples sintered above 1040°C only changed slightly while f≤400kHz. Meanwhile, the loss tangent (tanδ) was below 0.05 in a relatively wide frequency range in some samples, and a very low tanδ 0.028 was observed in the sample sintered at 1100°C for 16h with ε′=18,225 at 1kHz. These results indicate that the CaCu3Ti4O12 ceramics have a promising prospect in future applications with sufficiently low tanδ and high ε′.