Phase Structure and Dielectric Properties of Doped BaTiO_3 Ceramics

• 作 者: 李媛
• 机 构: Institute of Electronics and Information Engineering Tianjin University,,Tianjin 300072,China
• 出 处: Journal of Wuhan University of Technology(Materials Science
• 发表日期: 2007年03期
• 关键词: dielectric ceramic implies mutual symmetry radius ceramics ABO satisfy tetragona

The effects of two rare earth oxides such as CeO 2 and Sm 2 O 3 on the phase structure and dielectric properties of BaTiO 3 ceramic were investigated.Results indicate that the dielectric constant of this system will increase greatly with the increasing content of these two oxides,and Ce4+substitutes for Ba2+ located at A-site in ABO 3 structure.Quantitative XRD analysis shows that c/a ratio in the sample with addition of CeO 2 will increase,which implies the increase of tetragonality in system,causing the augment of dielectric constant,and the decrease of the crystal’s geometrical symmetry results in curie-temperature moving towards low temperature;Sm3+(0.096 nm)substitutes for Ba2+(0.135 nm)possessing larger radius in A-site and the electrovalency in A-site increases,the mutual effect is strengthened,so the polarization is enhanced,and the dielectric constant increases notablely.

The effects of two rare earth oxides such as CeO 2 and Sm 2 O 3 on the phase structure and dielectric properties of BaTiO 3 ceramic were investigated. Results indicate that the dielectric constant of this system will increase greatly with the increasing content of these two oxides. , and Ce4 + substitutes for Ba2 + located at A-site in ABO3 structure. Quantitative XRD analysis shows that c / a ratio in the sample with addition of CeO2 will increase, which implies the increase of tetragonality in system, causing the augment of dielectric constant, and the decrease of the crystal’s geometrical symmetry results in curie-temperature moving toward low temperature; Sm3 + (0.096 nm) substitutes for Ba2 + (0.135 nm) possessing larger radius in A-site and the electrovalency in A-site increases, the mutual effect is strengthened, so the polarization is enhanced, and the dielectric constant increases notablely.