Open AccessMicrostructures and electrical properties of CaCu3Ti4O12 ceramics
Author(s) -
Shoufu Shao,
Peng Zheng,
Jialiang Zhang,
Xiaokun Niu,
Chunlei Wang,
W. L. Zhong
Publication year - 2006
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.55.6661
Subject(s) - materials science , microstructure , dielectric , ceramic , grain boundary , crystallite , sintering , atmospheric temperature range , electrical impedance , composite material , optoelectronics , metallurgy , thermodynamics , electrical engineering , physics , engineering
CaCu3Ti4O12 ceramics are prepared by the conventional solid-state reaction method with various sintering temperatures. Microstructures 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—110 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.