Ab initio multiscale modeling of alloy surface segregation

Ab initio multiscale model for segregation at alloy surfaces was formulated by bridging the gap between first-principles DFT and large-scale MD-MC hybrid scheme with reactive force field formalism. The model enables first-principles-based quantitative prediction of large-scale composition change on alloy surfaces at different temperatures. Feasibility of the model is demonstrated by examining FeAl binary alloy surfaces with its surface composition change at several annealing temperatures. DFT total energy analysis confirms the qualitative segregation trend reported from the literature. The predictions from the multiscale segregation model are directly compared with experimental observations from the literature. The extendibility of the modeling framework towards ab initio predictions for multi-component alloy segregation behavior is also discussed.