Electronic and optical properties of Full-Heusler alloy Fe3−xMnxSi

Abstract

The electronic and optical properties of the nonstoicheiometric Heusler alloys Fe3−xMnxSi with (x = 0,0.75,1,1.25,2) have been studied by the first principles study in the framework of the density functional theory (DFT). Optical properties including the dielectric function, refractive index, energy-loss spectra, absorption spectra, optical conductivity and reflectivity were also calculated. Results show that the electronic structure of Fe3−xMnxSi alloys have half-metallic property for (x = 0.75,1,1.25). The real part of dielectric function has two main peaks in high energies. From absorption spectra it can be seen that absorption curves in low energy are broadened with respect to higher energies. The refractive index has a nonlinear dispersion in the energy range of 45–55 eV. The energy of plasmon peaks obtained from electron energy loss function (ELF) are about 25 eV.