CaCu3Ti4O12 陶瓷介电模量响应特性的研究

由于CaCu₃Ti₄O₁₂巨介电常数陶瓷的低频区直流电导较大, 本文采用模量 M"-f频谱表征与分析了低频和高频的两个松弛极化过程. 研究认为, 这两个特征峰属于晶界区Schottky 势垒耗尽层边缘深陷阱的电子松弛过程, 其中高频松弛峰起源于晶粒本征缺陷的电子松弛过程, 而低频松弛峰则为与氧空位有关的松弛极化过程. 对于CaCu₃Ti₄O₁₂这类低频下具有高直流电导的陶瓷材料, 采用模量频谱能更有效地分析研究其损耗极化机理. 关键词： 3Ti₄O₁₂陶瓷')" href="#">CaCu₃Ti₄O₁₂陶瓷 模量 松弛过程 电导

Dielectric modulus response of CaCu3Ti4O12 ceramic

The DC conductivity of the CaCu₃Ti₄O₁₂ ceramic is considerable at low frequency. The dielectric properties of the CaCu₃Ti₄O₁₂ ceramics are analyzed by dielectric spectrum, and the two relaxation processes are characterized by the dielectric modulus. The two relaxation processes are considered which are dominated by the electronic relaxation of deep bulk traps at the depletion layer edge. The low-frequency and high-frequency relaxation processes are attributed to oxygen-vacancy-related defect and native defect, respectively. It is proved that the modulus response of the CaCu₃Ti₄O₁₂ ceramic is equivalent to conductivity response at high temperature (low frequency), and the peak value of the M" is inversely proportional to capacitance. The activation energies calculated by conductivity and modulus are equivalent to each other. The modulus spectrum is more effective to the material which has high DC conductivity at low frequency such as CCTO ceramic.
Keywords： 3Ti₄O₁₂ ceramics')" href="#">CaCu₃Ti₄O₁₂ ceramics dielectric modulus relaxation polarization conductivity