First-Principles Study of Electronic, Magnetic, and Optical properties of the Intermetallic Compounds Ni ₃ Mn Doped with Al

Abstract

In this paper, we have calculated the electronic, magnetic, and optical properties of Ni₃Mn_{1 − x} Al _x (x = 0, 0.25, 0.50, 0.75), using a spin-polarized scalar relativistic linear muffin-tin orbital (SPR-LMTO) method within density functional theory (DFT). The spin–orbit coupling was included as a perturbation in the self-consistent iterations. In our calculations for densities of states, we have used in all alloys the energy (E) range from −10 to + 10 eV. And for the optical spectra in all alloys, we have used the same energy range from 0.083 to 5.640 eV. In this work, we have discussed the effect of Al substitution on the electronic, magnetic, and optical properties of Ni₃Mn intermetallics. We have calculated the coefficient of electronic specific heat, γ, for all these alloys; the values obtained are much larger compared to those in the constituent metals. We have found that the Al-doped Ni₃Mn maintains the ferromagnetic character and leads to a decrease in the local and total magnetic moments but improves the conductivity. Qualitatively, the line shape of the theoretical optical conductivity coincides well with the experimental data. The magnetic moments per formula unit are found to be in good agreement with observed theoretical and experimental values.