Mechanical and optical properties of inverse-perovskites Sc3InX (X = B, C, N)

作者：Hossain M A; Ali M S; Parvin F; Islam A K M A^*

来源：Computational Materials Science, 2013, 73: 1-8.

DOI：10.1016/j.commatsci.2013.02.017

• Sc3InX
• Mechanical properties
• Fermi surface
• QUANTUM-ESPRESSO
• Quasi-harmonic Debye model
• Thermodynamic properties
• Optical properties

We present first-principles density functional theory (DFT) investigations of mechanical, thermodynamic and optical properties of synthesized inverse-perovskites Sc3InX (X = B, C and N). The elastic constants at zero pressure and temperature are calculated and the anisotropic behavior of the compounds is illustrated. All the three materials are shown to be brittle in nature. The computed Peierls stress, approximately 3-5 times larger than in a selection of MAX phases, show that movement may follow but with much reduced occurrences compared to these MAX phases. The Mulliken dislocation bonding population and charge density maps show stronger covalency between Sc and X atoms compared with Sc-Sc bond. The Vickers hardness values of Sc3InX are predicted to be between 3.03 and 3.88 GPa. The Fermi surfaces of Sc3InX contain both hole- and electron-like topology which changes as one replaces B with C or N. The bulk modulus, specific heats, thermal expansion coefficient, and Debye temperature are calculated as a function both temperature and pressure using the quasi-harmonic Debye model with phononic effects. The results so obtained are analyzed in comparison to the characteristics of other related compounds. Moreover optical functions are calculated and discussed for the first time. The reflectivity is found to be high in the IR-UV regions up to similar to 10.7 eV (Sc3InB and Sc3InC) and 12.3 eV (Sc3InN), which would predict these to be good coating materials.

• 出版日期2013-6