Atomic Displacements and Valence Electron Structure in Orthogonal SrBi2Ta2O9 Ferroelectrics

作者：Xiao Xiaohong^*; Li Shichun; Jiang Shuying

来源：Rare Metal Materials and Engineering, 2015, 44(12): 3119-3123.

• bismuth layered ferroelectrics
• atomic displacement
• empirical electron theory
• valence electron structure
• spontaneous polarization

According to the space group theory of crystal, the atomic displacements in ferroelectric phase transition of the tetragonal SrBi2Ta2O9 crystal was calculated on the basis of the crystal structure parameters of the orthorhombic SrBi2Ta2O9 crystal. The result show that the spontaneous polarization of SrBi2Ta2O9 is along the a-axis. Furthermore, the valence electron structure of orthorhombic SrBi2Ta2O9 crystal was studied using the EET theory, and the number of the effective valence electrons of each atom in SrBi2Ta2O9 crystal was obtained. The spontaneous polarization of SrBi2Ta2O9 is 18.14 mu C/cm(2), which was calculated from the atomic displacements and atomic effective valence electrons numbers. The result is in good agreement with other theoretical and experimental results.

• 出版日期2015-12
• 单位中国石油大学（华东）