First-principles calculations of electronic and optical properties of Fe(3-x)V(x)Al (x = 0-3) compounds.

We present calculations of the electronic and optical properties for Fe(3-x)V(x)Al (x = 0-3) compounds with the aim of studying the effect of increasing the concentration of vanadium. We also report calculations of the magneto-optical (MO) Kerr effect, which depends on the off-diagonal components of the optical conductivity (OC), for the magnetic compounds Fe(3)Al and V(2)FeAl. This systematic analysis of the electronic structure and optical properties of Fe(3-x)V(x)Al compounds has been carried out using the full potential linearized augmented plane wave (FPLAPW) method within the generalized gradient approximation (GGA). The results, presented at equilibrium lattice constant, show that the compounds Fe(3)Al, V(2)FeAl and V(3)Al are metallic whereas the Fermi level lies at the 'pseudogap' in Fe(2)VAl. The OC spectra exhibit one main peak around 2.5 eV for all the compounds. The calculated OC spectra for Fe(2)VAl and Fe(3)Al shows the same features as in the experimental spectra, resulting a good qualitative agreement: however, the magnitude is overestimated. The blueshifting of structures in Fe(2)VAl is discussed. Our results show that the two compounds exhibit a contrast in terms of intraband transitions which help to achieve a good agreement with experiment in Fe(3)Al and remain at low key in Fe(2)VAl. The peaks in the optical conductivity can be explained as arising out of the transitions from Al p to Fe 3d and/or V 3d in these compounds. The calculations for MO spectra of the compounds Fe(3)Al and V(2)FeAl show small Kerr rotations.