物理学报2012，Vol.61Issue(19)：456-463,8.
氧含量对CaCu3Ti4O12巨介电常数和介电过程的影响
Effect of oxygen content on giant dielectric constant and dielectric process in CaCu3Ti4O12
摘要
Abstract
Dielectric properties of three different CaCu3Ti4O12 ceramic samples sintered, respectively, in vacuum, air and oxygen are investigated. Three plateaus are detected in the dielectric temperature spectra within 10-300 K for all the three samples, meanwhile the three corresponding peaks of the real impedance and imaginary capacitance occur at a certain temperature. However, the sample sintered in vacuum presents a higher dielectric and clearer real impedance and imaginary capacitance peak, which indicates that oxygen concentration and oxygen vacancy have a great influence on the dielectric property of CaCu3Ti4O12. The results reveal that the three plateaus observed in the dielectric temperature spectra come from the grain, grain boundary and the oxygen vacancy sitting in grain boundary, respectively. The analysis of dielectric spectra indicates that the activation energy of the grain is related to the sintering atmosphere and the oxygen vacancy results in a variable-range-hopping conductivity and polarization for the grain. The activation energy of oxygen vacancy trapper is about 0.46 eV and is nearly independent of sintering atmosphere. The high dielectric constant at low-frequency or high temperature is caused by oxygen vacancy trapping carriers in CaCu3Ti4O12.关键词
CaCu3Ti4O12/巨介电常数/氧空位/陷阱态Key words
CaCuaTi4O12/colossal dielectric constant/oxygen vacancy/trapping states分类
化学化工引用本文复制引用
杨昌平,李旻奕,宋学平,肖海波,徐玲芳..氧含量对CaCu3Ti4O12巨介电常数和介电过程的影响[J].物理学报,2012,61(19):456-463,8.基金项目
国家自然科学基金（批准号：11074067,11174073）和教育部新世纪优秀人才支持计划（批准号：NCET-08-0674）资助的课题. （）
