Electronic, magnetic and elastic properties of ε-phases Fe3X(X=B, C, N) from density-functional theory calculations

► The phase stabilities grow up from ε-Fe3B, θ-Fe3N, ε-Fe3C, θ-Fe3C, θ-Fe3B to ε-Fe3N. ► The bonding characters of ε-Fe3X are the mixtures of metallicity, covalence and ionicity. ► The Ms of the ε-Fe3B, ε-Fe3C and ε-Fe3N are 1.53, 1.61 and 1.66 μB/atom, respectively. ► The Debye temperatures (θD) of ε-Fe3X (X=B/C/N) are predicted as 427, 565 and 555 K.