中文摘要：

采用传统固相反应法制备了CaCu3Ti4O12陶瓷.XRD证实其CaCu3Ti4O12相;SEM观察到明显的晶粒晶界结构,晶界区亦由小晶粒构成;结合EDS结果,判定晶界区小晶粒为CuO.在较宽的温度范围内,CaCu3Ti4O12陶瓷的介电常数保持在105左右;当频率为103Hz温度小于150 K时,介电常数迅速下降.在173—373 K温度范围内,通过其I-V特性,得到CaCu3Ti4O12陶瓷直流电导随温度的变化：直流电导与温度的关系可分为三部分,对应的活化能分别为0.681 eV,0.155 eV和0.009 eV,这与CuO陶瓷直流电导活化能一致.可以认为晶界区的CuO小晶粒在CaCu3Ti4O12陶瓷的直流电导中占主导,这为解释CaCu3Ti4O12陶瓷反常的介电性能提供了新的思路.

英文摘要：

CaCu3 Ti4Ol2were prepared using conventional solid state reaction processing techniques of ceramic. The CaCu3 Ti4O12 crystalline phase was verified by XRD patterns. From SEM micrographs, obvious grain and grain boundary structures were observed, and the grain boundary region was comprised of small grains, which were found to be CuO, by EDS, the dielectric constant almost remains at a constant value of 105 in a wide temperature range, but drops dramatically at the frequency of 103 Hz when temperature is below 150 K. The relationship between conductance and temperature of CaCu3Ti4 O12 was obtained through the I-V characteristics measured in the temperature range from 93 K to 373 K. It can be separated into three parts with the corresponding activation energies of 0.681, 0.155 and 0.009 eV, which are consistent with the activation energy of CuO ceramics. It was concluded that the small CuO grains in the grain boundary region dominated the DC conductance in CaCu3 Ti4 Oi2 ceramics. Thus a new approach for explaining the extraordinary dielectric properties was provided.