Influence of Zirconium doping on microstructure and dielectric properties of CaCu3Ti4O12 synthesized by the sol-gel method

Giant dielectric response of CaCu3Ti4O12 prepared by the solegel method was enhanced by doping of Zr ions at the Ti site (CaCu3Ti4-xZrxO12, x = 0, 0.05, 0.1 and 0.2). CaCu3Ti3.95Zr0.05O12 ceramics can bring an increase in the main grain size and exhibit a very high dielectric constant (epsilon' > 2 x 10(4)) at room temperature over the frequency range of 20 Hze400 kHz. The fluctuation of epsilon' is less than +/- 20% in the temperature range of 20-180 degrees C while f = 200 kHz. Besides, the dielectric loss (tan delta) was below 0.05 in a relatively wide frequency range, and a very low tan delta of 0.026 was observed for the sample sintered at 1100 degrees C for 16 h with epsilon'similar to 2.35 x 10(4) while f = 10 kHz. Remarkably, these results indicate that Zr doping may improve the dielectric properties of CaCu3Ti4O12. (C) 2015 Elsevier B.V. All rights reserved.