Electronic structures and hyperfine interactions of YFe₁₀Mo₂ and YFe₁₀Mo₂Z (Z = H, N)

Mössbauer spectra and self-consistent spin-polarized electronic structures of YFe₁₀Mo₂ and YFe₁₀Mo₂Z (Z = H, N) are reported. The Mössbauer data were analyzed with the aid of band calculations. The calculations show that the sequence of hyperfine fields for the Fe sites in the parent alloy is changed by nitrogenation while it remains unchanged upon hydrogenation. The analyses of the local magnetic moments μ_loc, Fermi-contact hyperfine fields (H_FC) and the isomer shifts (IS) at different Fe sites in YFe₁₀Mo₂ and YFe₁₀Mo₂ (N, H) show that the effect of the interstitial atoms is stronger for N than that for H and the effect of the interstitial atoms on magnetic moments and hyperfine fields depends on the chemical properties of the Z atoms. The calculated isomer shifts (IS) and hyperfine fields (H_FC) are compared with the results of Mössbauer-spectroscopy experiments.