Enhancement of Giant Dielectric Response in CaCu_3Ti_4O_(12) Ceramics by Zn Substitution

摘要

Zn-substituted CaCu_3Ti_4O_(12) ceramics were synthesized by solid-state sintering. Their microstructures and dielectric properties were investigated. Ca(Cu_(1-x)Zn_x)_3Ti_4O_(12) single-phase structnres were obtained up to x = 0.1, and the Cu~+/Cu~(2+) and Ti~(3+)/Ti~(4+) mixed-valent structure was enhanced with increasing Zn substitution. The giant dielectric response was significantly enhanced by Zn substitution. The dielectric constant increased with increasing x, and a giant dielectric constant plateau as high as ～9 × 10~4 was achieved for x = 0.1 at 10 kHz, while that for x = 0 was ×3 × 10~4. The enhanced giant dielectric response was profoundly concerned with the modified mixed-valent structure.