CaCu_3Ti_4O_(12)陶瓷的微观结构和电学性能  

Microstructures and electrical properties of CaCu_3Ti_4O_(12) ceramics

作　　者：邵守福[1] 郑鹏[1] 张家良[1] 钮效鹍[1] 王春雷[1] 钟维烈[1] 

机构地区：[1]山东大学物理系,济南250100

出　　处：《物理学报》2006年第12期6661-6666,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50572055);山东省优秀中青年科研奖励基金(批准号:2005BS04013).~~

摘　　要：利用传统的固相反应工艺,在不同的烧结温度下制备了一系列的CaCu3Ti4O12陶瓷样品,考察了其微观结构以及介电和复阻抗方面的电学性质.研究发现这些样品在微观结构方面可分为三种类型,高介电性与微观结构有着密切的关联性.室温下,样品的低频介电常数随陶瓷晶粒尺寸的增大而提高.随着测试温度的升高,不同微观结构类型的样品呈现出不同的电学性质的变化,但其中也存在着一些相同的特征.高温下,介电频谱呈现出一个低频介电响应和两个类Debye型弛豫色散,复阻抗谱呈现出三个Cole-Cole半圆弧.将实验上观测到的电学性质的起因归于陶瓷多晶微结构中的晶畴、晶界和晶粒内的缺陷.CaCu3Ti4O2 ceramics are prepared by the conventional solid-state reaction method with various sintering temperatures. Mierostructures are examined by scanning electronic microscopy, and it is found that they could be categorized into three different types. Dielectric properties and complex impedances are investigated in the frequency range of 40 Hz-ll0 MHz over a temperature range of 25-280 ℃ . The room temperature dielectric constant increases with sintering temperature. With increasing the measuring temperature, ceramics with different microstructures show diverse electrical properties. However, some common features exist among the electrical properties. For all of the ceramics, dielectric dispersion shows a low-frequency response and two Debye-type relaxations, and there exist three semicircles in the complex impedance plane at high temperatures. The observed electrical properties are ascribed to the detailed internal polycrystalline microstructure, i.e., to come from the contributions of the domains, the grain boundaries and defects inside grains such as domain boundaries, etc.

关 键 词：CACU3TI4O12 微观结构 电学性质 

分 类 号：O482.4[理学—固体物理]