A comparative atomic simulation study of the configurations in M-Al (M = Mg, Ni, and Fe) nanoalloys: influence of alloying ability, surface energy, atomic radius, and atomic arrangement

摘要

The structure evolution behavior of M-Al (M = Mg, Ni, and Fe) nanoalloys with three sizes (N = 13, 55, and 147) at different compositions were studied through basin-hopping Monte Carlo and molecular dynamics simulations. The atomic interaction was described using the embedded atom method. Results showed that the particle size and composition ratio of each element affected the final configuration of nanoparticles mainly due to the competition between the alloying effect and surface segregation. Among three different systems, the Ni-Al system had the strongest alloying effect, followed by Fe-Al and Mg-Al systems. Among three types of nanoalloys with 13 atoms, the icosahedra (ICO) structure had the most stable configuration. For nanoalloys with 55 and 147 atoms, poly-icosahedral (pIh), three-layer onion-like, rhombohedra (RHO), and core-shell structures were observed by controlling the composition ratio of two different metals. This study can provide theoretical guidance for the laboratory synthesis of nanoalloys with different structures.