Magnetovolume and chemical bonding effects of Sn atom in the γ′-(Fe1-xSnx)4N compounds

Combining x-ray diffraction and high pressure Mosshauer spectroscopy, the structure and the hyperfine parameters of Sn substituted for Fe in γ′-Fe4N were in- vestigated. The results of x-ray diffraction indicate that single phase γ′-(Fe1-xSnx )4N compounds can be synthesized in the composition range 0_≤x ≤ 0.3, and the lattice parameter can be well fitted with two linear formulas α0(x) = 3.795+0.019 × （0.0≤ x ≤0.10） and α0(x)= 3.795 + 0.228 × (x -0.1) (0.10 ≤ x ≤ 0.30) for different, content of Sn. Using high pressure Mossbauer spectra. the influences of the magnetovolume effect and the chemical bonding effect of Sn atom on the hyperfine magnetic field and the isomer shift were first distinguished. It is found that the magnetovolume and the chemical bonding have different influences on the properties of γ′-(Fe1-xSnx)4N, and the latter plays a more important role.