Stability of Zener order in martensite: an atomistic evidence

Martensite is a supersaturated solid solution of carbon in body-centered iron wherein interstitial atoms preferentially occupy single octahedral sublattice. Despite century research, the mechanism this long-range ordering still subject debate. Recently, Zener’s theory was challenged both experimentally and theoretically. In an attempt to settle controversy, we investigated by density functional ground states Fe-C configurations having various degrees order. We conclude that fully Zener-ordered are always most stable energetically, thus confirming theory. Comparison with mean-field elasticity Ising-type modelling supports elastic origin Zener ordering.