Electronic Structure and Optical Properties of the Co2NiAl Heusler Alloy

Resumo

The frequency dependences of the real part ε₁(ω) and imaginary part ε₂(ω) of the complex dielectric constant of the Co₂NiAl Heusler alloy are studied in a region of spectrum of 0.08–5 eV. It was found that the character of variations of the spectral parameters of the Co₂NiAl ally is typical of media with metallic conductivity. In the IR region, the mechanism of intraband acceleration of electrons by the field of light wave dominates. The contribution of interband electron transitions is marked even at the energies E ≥ 0.15 eV. Results of the investigations are discussed based on the performed electronic structure calculations. It is shown that the main contribution to the resulting optical conductivity dependence is made by interband electron transitions in the band with spins opposite to the magnetization direction.