Physical properties of α-Fe upon the introduction of H, He, C, and N

•Physical and mechanical properties of α-Fe are strongly affected by H, He, C, and N.•H and He are stable at the T-site and C and N are stable at the O-site in α-Fe.•H, He, C, and N cause structural elongation of α-Fe.•C and N decrease the magnetic moment of Fe.

The effects of impurities of H, He, C, and N in α-Fe are investigated in terms of electronic structures using the density functional theory. Calculations reveal that H and He are stable at the T-site while C and N are stable at the O-site within α-Fe. The local strain field by H, He, C, and N in α-Fe causes structural elongation. Furthermore, the decrease of magnetic moment of Fe upon the introduction of C and N is found where the charge transfer is responsible. H, He, C, and N affect the electronic structure of α-Fe and change the fundamental physical properties of α-Fe.