Effects of ZrO_2 additions on the dielectric properties of CaCu_3Ti_4O_(12)

摘要

The dielectric spectra of CaCu_3Ti_4O_(12) is characterized by a large permittivity (ε_r > 10000) with only a weak dependence on temperature over the temperature range 200-400 K. In this work, doping with 0.1-1.0 wt % ZrO_2 has been shown to dramatically reduce the dielectric loss. At 0.5 wt % ZrO_2, tan δ remains below 0.05 over the frequency range 50 Hz-30 kHz and is just 0.065 at 100 kHz. While there is some diminution of the permittivity (ε_r ≈ 5000 at 10 kHz) Zr-doped ceramics, exhibited very little bias dependence (ΔC/C_0< 1.0% up to 40 V). In summary, results suggest that ZrO_2 doping is an effective method for maintaining a high permittivity and low loss over a broad range in temperature, bias, and frequency.