Dielectric Properties of BaTiO₃-Modified BiFeO₃ Ceramics

Abstract

Multiferroic BiFeO₃ has attracted extensive interest due to its potential in several applications. However, pure-phase BiFeO₃ is very difficult to obtain. Hence, mixing BiFeO₃ with other ferroelectrics, such as BaTiO₃, is another approach to obtain materials with possible multiferroic properties. In this study, the BiFeO₃ was modified with addition of BaTiO₃ via a simple solid state reaction method. Dielectric properties of the BaTiO₃-modified BiFeO₃ ceramics were investigated over wide range of temperature and frequency. The results show that the (1-x)BiFeO₃-xBaTiO₃ ceramics with x = 0.1 and 0.2 exhibited large dielectric properties with giant-dielectric-like behavior. The dielectric properties were seen to improve with increasing BaTiO₃ content, with the highest dielectric constant (ϵ_r = 19000) observed in 0.8BiFeO₃-0.2BaTiO₃ ceramic. The results were explained in terms of the pre-dominantly intrinsic BiFeO₃ giant-dielectric behavior as a result of Fe multivalent states, as well as a better grain packing density with increasing BaTiO₃ content.

Keywords:

• Dielectric properties
• BiFeO₃-BaTiO₃

Acknowledgment

This work was financially supported by the Industry/University Cooperative Research Center (I/UCRC) in HDD Component, the Faculty of Engineering, Khon Kaen University and National Electronics and Computer Technology Center, National Science and Technology Development Agency (NSTDA). The author (S.C.) is also thankful to the Young Scientist and Technologist Program (YSTP) for the undergraduate scholarship and the Synchrotron Light Research Institute (Public Organization) for PhD scholarship and Suranaree University of Technology for additional support.