New insights on clusters stacking mechanism within medium range in Fe-Al amorphous alloys

Molecular dynamics simulation has been employed to investigate the stacking mechanism of short-range-order structures in Fe-Al amorphous alloys. We explore the effect of Al content (0–50 %) on the nearest-neighbour correlation index and stacking degree between their main clusters. The results show that the correlation index changes little over the Al content range, and the stacking degree decreases with the Al content increasing on the whole. Through the spatial correlation analysis, it is found that the clusters with similar structural symmetry are more likely to connect. Moreover, we find that the stacking degree depends on the number of clusters and their correlation index, i.e., the stacking degree is found to increase as the number or correlation index of clusters increases, but the cluster number shows a greater influence on the stacking degree compared to their correlation index. We believe that these are the inherent stacking features in medium range in Fe-Al amorphous alloys, which can also be extended to other amorphous alloys. This work provides a deeper insight into the spatial relationship of short-range-order structures and the stacking of clusters from short to medium range.