The hyperfine properties of iron-gallium alloys

The hyperfine properties at Fe site in iron-gallium alloy are calculated using the full-potential linear-augmented-plane-waves method. We have calculated the Fermi contact field (B_hf) and isomer shift (δ) at the Fe site versus the number of neighbouring Ga atoms. We found that B_hf decrease whereas δ increases with increasing number of neighbouring G atom. In addition we have calculated the hyperfine properties of FeGa system with DO₃ structure, where various distributions of 4 the Ga atoms in the conventional unit cell are considered (including the regular DO₃ structure). We found that the DO₃ structure has the lowest energy as compared to the other configurations. The two distinct A and D sites of the ordered DO₃ conventional unit cell have two distinct values for B_hf and δ. On changing the atomic arrangement of the Ga atoms within the conventional unit cell, the configuration of the A site is maintained whereas that of the D site becomes imperfect. The contact magnetic hyperfine fields of the D-like sites in the imperfect structures are lower than that of the DO₃D site.