Electronic, magnetic, optical and elastic properties of Fe2YAl (Y=Ti, V and Cr) using first principles methods

Using first principles computations, we have investigated the structural, electronic, magnetic, optical and elastic properties of Fe2YAl (Y=Ti, V and Cr) Heusler alloys. The present study reveals that for the majority-spin state, Fe2CrAl compound has high density of states and shows a 100% spin polarization in the vicinity of the Fermi level. Our results also suggest that both the electronic and magnetic properties and also the Fermi surface of the Fe2CrAl are intrinsically related to the appearance of the minority-spin gap. The origin of energy gap in the minority-spin states is discussed in terms of the d-d hybridization between the Fe and Cr atoms. The Fermi surface structure and optical properties are explored within the framework of the full potential linearized augmented plane wave (FP-LAPW) method. The origin of Fermi surface structure is discussed in terms of energy bands in the majority-spin states near the Fermi level. The calculated dielectric functions and other optical properties are found to be in good agreement with earlier experimental results. In addition, the independent elastic constants of these Heusler alloys are also derived from the derivative of total energy as a function of lattice strain in full detail. The analysis of the ratio between the bulk and shear moduli confirms that all three compounds are found to be brittle in nature. Furthermore, as a representative case, we have also carried out the spin-polarized relativistic Korringa-Kohn-Rostoker (SPR-KKR) method based on calculations to obtain the magnetic Compton profiles (MCPs) for momentum transfer along [100], [110], and [111] principal directions and also investigated the anisotropy in the spin-dependent Compton profiles.