The Effect of GeO₂ and In₂O₃ Doping on the Dielectric Properties of CaCu₃Ti₄O₁₂ Ceramics Prepared via Vibro-Milling Method

Abstract

In this work, effects of GeO₂ and In₂O₃ doping on the dielectric properties of CCTO were investigated. Doping levels range from 0.5 to 2.0 mol%. The vibro-milling method was employed for processing. The dopant addition produced a slightly smaller grain size. A reduction in dielectric constant was observed, but it is still high. The 2.0 mol% GeO₂ and In₂O₃ doped samples exhibited high dielectric constant of about 25,000 and 23,000 and low dielectric loss with 0.06 and 0.05 respectively at room temperature and at 10 kHz. The dielectric measurements showed that the modified samples exhibited a strong dielectric independency of temperature and frequency. In addition, the loss tangent reduced after doping. From this results, it can be incurred that GeO₂ and In₂O₃ doping, processed via vibro-mill are the suitable methods to achieve the stability of high ϵ_r and low loss ceramics.

Keywords:

• High dielectric material
• dielectric properties
• microstructure

Acknowledgments

This work was supported by Development and Promotion of Science and Technology Talents Project (DPST), Thailand, Faculty of Science and Graduate School Chiang Mai University, the Thailand Research Fund (TRF), and Office of the Higher Education Commission (OHEC).