Optical properties of Fe-Mn-Ga alloys

The first-principles calculations of the electronic structures and the interband optical conductivity (OC) spectra have been performed for the stoichiometric Fe2MnGa alloy with L21 and L12 types of atomic ordering. The calculated optical properties of Fe2MnGa alloy for the L21 and L12 phases are complemented by the experimental OC spectra for bulk and thin film Fe-Mn-Ga alloy samples near the stoichiometry 2:1:1 with L21 and L12 (for bulks) as well as the body-centered-cubic and face-centered-cubic (for films) structures, respectively. A reasonable agreement between experimental and calculated interband OC spectra was obtained for both phases of the alloy. The experimental data show no significant difference in the OC spectra with respect to the degrees of atomic and magnetic orders of the samples.