Magnetism and Optical Property of Mn-Doped Monolayer CrSi2 by First-Principle Study

We investigate magnetism and optical properties of intrinsic and Mn-doped monolayer CrSi2 using the first-principle methods based on density functional theory. The results show that both monolayer CrSi2 sheets are metallic and ferromagnetic (FM) that hold promise in future 2D magnetic devices. In spite the slight reduction of the total magnetic moment of system after Mn doping in monolayer CrSi2, the formation energies of ferromagnetic CrSi2 are also reduced. So, Mn doping in monolayer CrSi2 can have more promising applications in spintronics and magnetic storage. The optical properties of monolayer CrSi2, including the absorption spectra, reflectivity, refractive index, loss function and dielectric function are also calculated. The intensity of reflectivity in far-infrared ranges is enhanced and real part n of refractive index decreases after Mn doping. The real part n of the refractive index is nearly constant (Ee1) beyond 13 eV indicating that monolayer CrSi2 is vacuum like and fully transparent.