First‐Principles Study on Stacking Fault Energy of Disordered γ-Fe1 − xMnx with Antiferromagnetic Configuration

The stacking fault energy (SFE) of Fe-Mn alloys is studied by first-principles calculations with chemical disorder and order, nonmagnetic (NM) and antiferromagnetic (AFM) configurations. It is found that Mn atom has a short-range effect on both nonmagnetic and antiferromagnetic stacking faults (SF) plane. Mn atom reduces the intrinsic stacking fault energy (ISFE) and unstable stacking fault energy (USFE) when it is in the vicinity of the SF plane. Short-range effect is 42% in AFM configuration larger than 12.6% in NM configuration when Mn atom is on SF plane. The phenomenon of generalized stacking fault energy (GSFE) curve and short-range effect are investigated by topological analysis and electron structures respectively. Furthermore, the twinning tendency is proven to be stronger in AFM γ-FeMn with increasing Mn concentration than other deformation mechanisms. Stacking fault energy of disordered γ-Fe1-xMnx with antiferromagnetic configuration is calculated by VASP+SQS method. We analyze the “short-range effect” of Mn atom and illustrate the relationship between stacking fault energy and deformation mechanism in γ-Fe1 − xMnx