Effect of the MgO substitution for CuO on the properties of CaCu3Ti4O12 ceramics

被引：25

作者：

Hu, Yi ^{[1
]}

Jeng, Tian-Syuan ^{[1
]}

Liu, Jiun-Shing ^{[1
]}

机构：

[1] Tatung Univ, Dept Mat Engn, Taipei 104, Taiwan

来源：

CERAMICS INTERNATIONAL | 2012年 / 38卷 / 04期

关键词：

Impedance; Giant dielectric; Ceramics; Substitution; GIANT DIELECTRIC-CONSTANT; MICROSTRUCTURES; DECREASE;

D O I：

10.1016/j.ceramint.2011.12.059

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

In this work, the effect of MgO substitution for CuO on the dielectric properties of CaCu3Ti4O12 (CCTO) was studied. Ceramic samples of CaCu3-xMgxTi4O12 were prepared by a two-step solid-state reaction. The samples were sintered at 600 degrees C for 2 h and then heated to the final sintering temperature of 1100 degrees C for 8 h. The lattice parameter of CCTO decreases with Mg substitution from X-ray diffraction (XRD) analysis, since the ionic radius of Mg2+ is smaller than that of Cu2+. Mg substitution in CCTO causes apparent change in microstructure with much smaller grains due to the grain growth inhibition. The maximum of the dielectric constant can reach to 7.8 x 10(5) at f = 100 Hz for Mg substitution with x = 0.6. The sample with Mg substitution (x > 0.2) yields an apparent semicircle in the impedance spectra. The correlation between the microstructure and dielectric properties suggests the presence of a thin barrier layer forming at the grain boundary. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

引用

页码：3459 / 3464

页数：6

共 29 条

[1] Characterization of grain boundary impedances in fine- and coarse-grained CaCu3Ti4O12 ceramics -: art. no. 094124 [J].