Preparation and properties of B-site Zn²⁺ substituted CaCu₃Ti₄O₁₂ ceramics

Zn²⁺ substitution for B-site ions of CaCu₃Ti₄O₁₂ ceramics were prepared by solid-state reaction, which were deeply investigated by the X-ray diffraction and the scanning electron microscopy as well as an impendence analyzer. The dielectric permittivity of Zn²⁺ ions doped CaCu₃Ti₄O₁₂ is 6545 and the dielectric loss is less than 0.4 in 10 kHz-1 MHz frequency range, The optimized properties of Zn²⁺ substituted CaCu₃Ti₄O₁₂ are related to the increase of grain boundaries resistance and grain size. Temperature dependences of the dielectric permittivity and loss of CaCu₃Ti_4-xZn_xO_12-δ (x=0.03) ceramics were measured and the active energy is 0.529 eV, thus the dielectric relaxation is coupling among grain boundaries.