Stability and properties of alloyed ε-(Fe1−xMx)3N nitrides (M = Cr, Ni, Mo, V, Co, Nb, Mn, Ti and Cu): A first-principles calculations.

By using the first-principles calculations within virtual crystal approximation (VCA) framework, the alloying behavior of transition metals M (M = Cr, Ni, Mo, V, Co, Nb, Mn, Ti and Cu) has been investigated in ternary ε-(Fe 1 − x M x ) 3 N nitrides ( x = 0–0.15). The phase stability and elastic properties are studied by calculating the formation Gibbs energy, independent elastic constants and densities of states. The calculated results show that the stability of the ε-(Fe 1− x M x ) 3 N nitrides decrease with the increase of the substitution content, indicating the decomposition of ε phase to α or γ′ phases. The elastic properties of the ε-(Fe 1− x M x ) 3 N nitrides are sensitive to the transition element types except Co and Mn which show the weakest effect. Densities of states are given for all ε-(Fe 1− x M x ) 3 N nitrides to confirm the origins of the variations of phase stability and elastic properties. The calculated results show a reasonable agreement with available experimental values. [ABSTRACT FROM AUTHOR]