中文摘要：

采用固相法制备0.85Bi4Ti3O12-0.15Li Nb O3-0.75%Ce O2（BTO-LN-0.75Ce）铋层状压电陶瓷。通过阻抗谱研究不同温度和频率对样品电性能的影响。结果表明：介电常数ε＊的实部ε′和虚部ε″在低频区域出现分散现象;随频率增大,阻抗（Z＊）的实部Z′值逐渐减小,而虚部Z″值先增大后减小。阻抗Cole-Cole图表明：晶粒内部对电传导过程起主作用,并可用一个并联电阻–电容电路等效。陶瓷样品的阻抗值随温度的升高而减小,电导率值在低频区域相对稳定,且电导率满足Arrhenius关系,说明陶瓷样品的电导是热激活的过程。BTO-LN-0.75Ce的电导活化能小于BTO-LN的电导活化能,分别为1.591 9和1.756 2 e V。

英文摘要：

The cerium modified 0.85Bi4TiaO12-0.15LiNbO3-0.75%CeO2 （BTO-LN-0.75Ce） piezoelectric ceramics were synthesized by a conventional solid state processing. The effects of temperature and frequency on the electrical properties of ceramics were investigated. The results show that the real （ε＇） and the imaginary （ε＂） parts of permittivity both appear dispersive at low frequencies. The values of the real （Z＇） part of impedance （Z＊） decrease, and the values of the imaginary （Z＂） part firstly increase and then decrease with increasing frequency. According to the Cole-Cole plots, the grain interior is a major contribution to the electrical conduction process as a parallel resistance-capacitance equivalent circuit. The semicircles become smaller when temperature increases, indicating that the impedance decreases with the increase of temperature. The stabilized conductivity appears in the low frequency region at high temperatures. The conductivity obeys the Arrhenius law, showing the thermal activation of the process. The grain activation energy, Eal（g）, of BTO-LN-0.75Ce （i.e., 1.591 9 eV） is lower than Ea2（g） of BTO-LN （i.e., 1.756 2 eV）. Key words： bismuth layer-structured; piezoelectric ceramics; complex impedance spectrum; conductivity