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

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 20 Hz and 2 MHz, and the dielectric constants (epsilon') of CaCu3Ti4O12 ceramic samples sintered above 1040 degrees C only changed slightly while f <= 400 kHz. Meanwhile, the loss tangent (tan delta) was below 0.05 in a relatively wide frequency range in some samples, and a very low tan delta 0.028 was observed in the sample sintered at 1100 degrees C for 16 h with epsilon' = 18,225 at 1 kHz. These results indicate that the CaCu3Ti4O12 ceramics have a promising prospect in future applications with sufficiently low tan delta and high epsilon'. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.