Magnetic and Chemical Contributions to Interface: A Monte Carlo Simulation Study

This report studies implications of chemical and magnetical contributions to a Fe-Cr alloy using Monte Carlo simulations of a modified Ising Model. Through order parameter the properties of the alloy has been characterised and the phase diagram of Fe-Cr , which exhibits the main characteristics of the experimentally obtained phase diagram has been constructed. For low temperatures and intermediate concentrations a new ordered phase, which resembles the ternary Heusler alloy, has been found together with the corresponding phase boundary. The Variance Constrained Semi-Grand Canonical ensemble was successfully applied to compute the interface free energy as a function of concentration and the value of the interface free energy in the [100]-direction has been computed. From the interface free energy the miscibility gap, where phase separation between chromiumrich and iron-rich clusters form, has been constructed. Also the spinodal, the limit of where metastable phases can exist, has been found. A pronounced size dependence of the difference between spinodals and binodals has been found and the assumption that the difference at system size of 20³ is negligible is proven to be wrong.