Thermodynamic Stability, Half-Metallic and Optical Properties of Sc2CoSi [001] Film: a DFT Study

Abstract

The electronic and optical characteristics of the Sc 2 CoSi Heusler with L21 structure and also the surface effect on electronic and optical properties, and the films thermodynamic stability of the [001] direction in four cases including: Sc-Sc, Sc-Co, Sc-Si and Co-Si terminations are studied using the first principles calculations (FPLAPW) within the framework of the density functional theory (DFT). The band structure calculations represent the ferromagnetic half-metallic properties with 100% spin polarization and 0.54 eV indirect gap in spin down for Sc 2 CoSi bulk with optimized lattice parameters of 6.25 Å. The total magnetic moment obtained for this compound is −1.0 μB, which is in accordance with Slater-Pauling rule. The half-metallic (HM) behavior by 100% spin polarization at Fermi level is occurred in the Sc-Si termination with a 0.32 eV gap in down spin. The optical responses have been calculated for the bulk and Sc-Si termination by a red shift in these parameters and the metallic treatments have been increased. According to the thermodynamic phase diagrams, it is shown the Sc-Si and Sc-Sc terminations are more stable than other terminations.