FIRST PRINCIPLES INVESTIGATION OF HALF-METALLIC MgSrB AND MgSrAl

A comprehensive study on optical, electronic and structural properties for MgSrB and MgSrAl has been conducted using density functional theory (DFT). The computations predict that MgSrB and MgSrAl are half-metallic compounds. The band gap in the up spin channel is 0.826 and 1.263 eV with PBE-GGA and mBJ for MgSrB. While, for MgSrAl, gap in the up spin channel is 0.477 eV with mBJ, and it is a spin-gapless semiconductor with PBE-GGA approximation. The optical properties of MgSrB and MgSrAl alloy were also examined, and the imaginary component of the dielectric function exhibits pronounced absorption peaks within the energy spectrum of 0.149 – 4.993 eV for the both alloys. These peaks result from transitions among different states of ions and atoms in these compounds. In general, our results indicate that MgSrB and MgSrAl half-Heusler alloys are good materials for optoelectronics, solar cells and spintronics.