Effects of Ta⁵⁺ doping on microstructure evolution, dielectric properties and electrical response in CaCu₃Ti₄O₁₂ ceramics

详细信息	查看全文 | 推荐本文 |

• 作者：Prasit Thongbai^a ; ^b ; ^{prasitphysics@hotmail.com} ; ^{pthongbai@kku.ac.th} ; Jutapol Jumpatam^a ; Teerapon Yamwong^c ; Santi Maensiri^d
• 关键词：Grain growth ; Grain boundaries ; Dielectric properties ; Electrical properties ; Capacitors
• 刊名：Journal of the European Ceramic Society
• 出版年：2012
• 期刊代码：53_09552219
• 类别：ms
• 出版时间：August, 2012
• 卷：32
• 期：10
• 页码：2423-2430
• 文件大小：1030 K

摘要

The effects of Ta⁵⁺ substitution on the microstructure, electrical response of grain boundary, and dielectric properties of CaCu₃Ti₄O₁₂ ceramics were investigated. The mean grain size decreased with increasing Ta⁵⁺ concentration, which was ascribed to the ability of Ta⁵⁺ doping to inhibit grain boundary mobility. This can decrease dielectric constant values. Grain boundary resistance and potential barrier height of CaCu₃Ti₄O₁₂ ceramics were reduced by doping with Ta⁵⁺. This results in enhancement of dc conductivity and the related loss tangent. Influence of charge compensations on microstructure and intrinsic electrical properties of grain boundaries resulting from the effects of replacing Ti⁴⁺ with Ta⁵⁺ are discussed. The experimental data and variation caused by the substitution of Ta⁵⁺ can be described well by the internal barrier layer capacitor model based on space charge polarization at the grain boundaries.