Dielectric properties and microstructure of Mg doped barium titanate ceramics

Abstract

Abstract

Pure and Mg doped barium titanate ceramics were prepared by conventional solid state reaction method. The crystal structure, surface morphology and dielectric properties of Mg doped barium titanate ceramics were investigated. Mg²⁺ ions have entered the unit cell maintaining the perovskite structure of solid solution without the evidence of any additional phase when Mg content is <1·5 at-%. When the Mg content is >1·5 at-%, the second phase of MgO has been found. It is found that the addition of Mg can inhibit grain growth of barium titanate ceramics. The Curie temperature and the dielectric constant peak decrease with increasing the MgO content. The addition of magnesium can lead to diffuse transition of barium titanate ceramics. As MgO content increases, the dielectric loss of Mg doped barium titanate ceramics increases.

Keywords:

• Magnesium
• Barium titanate
• Crystal structure
• Morphology
• Dielectric property

This work is supported by the Program for Excellent Talents in University of Chongqing, China, and the Natural Science Foundation of Chongqing, China (grant no. CSTC2010BB4286), and Research Foundation of Chongqing University of Science and Technology (the project no. CK2010Z05).