Anisotropic elasticity and thermal conductivities of (alpha, beta, gamma)-LiAlSi2O6 from the first-principles calculation

作者：Shou, Hongwei; Duan, Yonghua^*

来源：Journal of Alloys and Compounds, 2018, 756: 40-49.

DOI：10.1016/j.jallcom.2018.05.040

• First-principles calculation
• LiAlSi2O6
• Elastic properties
• Thermal conductivity

In this work, the first-principles calculation was employed to perform the investigations of the structural properties, elastic constants and moduli, anisotropy in elastic properties and thermal conductivities of (alpha, beta, gamma)-LiAlSi2O6. The obtained cohesive energies and formation enthalpies show that all LiAlSi2O6 are energetically stable and alpha-C2/c LiAlSi2O6 is the most stable phase. The elastic properties, including bulk, shear and Young's moduli (B, G and E), Poisson's ratio v and hardness H-V were computed based on the single-crystal elastic constants. alpha-C2/c LiAlSi2O6 has the largest G, E and H-V values. The elastic anisotropy was characterized by the elastic anisotropic indexes, surface constructions and projections of elastic modulus. It can be found that all LiAlSi2O6 show anisotropic elasticity and the order is alpha-P2(1)/c > gamma> beta> alpha-C2/c. The thermal conductivities and their anisotropy of LiAlSi2O6 were also discussed by Long's and Cahill's models, and the results indicate that all LiAlSi2O6 exhibit potential for insulation materials.

• 出版日期2018-8-5
• 单位昆明理工大学