Influence of interstitial distribution on the elastic and electronic properties of ε-Fe6NxCy phase by first-principles calculations

By using first-principles calculations, the influence of interstitial distribution on the elastic and electronic properties of ε-Fe6NxCy (x,y=1,2 and x+y=2,3) phase is investigated. Formation energy calculations exhibit the increasing stability of ε-Fe6NxCy phase with the increasing distance between the interstitial atoms, indicating a repulsive nature between the interstitial atoms. The theoretical elastic constants, bulk modulus (B), shear modulus (G), ratios of B to G, Youngʼs modulus (E), Poissonʼs ratio (v) of ε-Fe6NxCy phase are obtained. Density of states calculations reveal the electronic structure variations induced by interstitial distribution, by which the origins of the variations of stability and elastic properties are discussed.