Study of the electronic and optical properties of half-Heusler alloys CoCrSn

We investigate the electronic, structure and optical properties of half-Heusler compound CoCrSn using the Full-Potential Linearized Augmented Plane Wave Method (FLAPW) within generalized gradient approximation(GGA) and generalized gradient approximation including Hubbard U-parameter (GGA + U) for the exchange correlation term of the effective Hamiltonian based on the density functional theory(DFT). Structural optimizations were carried out for both compound which revealed that the ferromagnetic (FM) state was more stable than nonmagnetic (NM) state. So, in the (FM) state the equilibrium lattice parameter was 5.8540 Å for CoCrSn. The alloy was found to be nearly half metallic (HM) at equilibrium cell volume. Basic optical properties like dielectric function, reflectivity, energy loss function, absorption coefficient were hence determined for a range of photon energy up to12 eV (ultraviolet region).