A first-principles investigation of structural properties, electronic structures and optical properties of beta- and gamma-LiAl(SiO3)(2)

作者：Zhang, Junhui; Duan, Yonghua^*; Li, Chengxiu

来源：Ceramics International, 2017, 43(16): 13948-13955.

DOI：10.1016/j.ceramint.2017.07.126

• Lithium aluminosilicate
• Band structure
• Density of state
• Optical constants

By applying the first-principles calculations within the generalized gradient approximation (GGA), the structural properties, electronic structures, and optical constants for the lithium aluminosilicate materials (beta- and gamma-spodumenes) were investigated in this work. The calculated cohesive energy and formation enthalpy indicate that beta-spodumene is more stable than gamma-spodumene. Band structure results show that beta-spodumene is a direct gap insulator (G-G) with a gap width of 5.063 eV and gamma-spodumene is an indirect band gap insulator (G-Z) with a gap width of 5.200 eV. The Mulliken analysis and charge density difference indicate that the order of bond strength is Si-O bond > Al-O bond > Li-O bond. The polycrystalline and directional optical properties were discussed, and the results reveal that the static refractive indices n(0) are 1.187 and 1.936 for beta- and gamma-spodumenes, respectively, and they are optically anisotropic.

• 出版日期2017-11
• 单位中国地质科学院; 昆明理工大学