Temperature effects on growth configurations of Al atoms on an Fe rhombohedron: a molecular dynamics simulation

The growth of Al atoms on an Fe rhombohedral nanoparticle with 1,105 atoms in the temperature range of 100–1,200 K is studied by molecular dynamics and embedded atom method. Several thermodynamics parameters, including potential energy, radial distribution function, and Lindemann index are used for the growth process analysis. This study reports an increasing energy per Fe atom and a decreasing energy per Al atom with increasing temperature. Alloying between Fe and Al atoms accelerates at higher temperatures, because of the incorporation of more Al atoms into the Fe core. Three different growth configurations are found for the simulations at different temperatures. At temperatures below 800 K, the core–shell configuration with Fe and Al as core and shell, respectively, is the most favorable. At approximately 800 K, a nanoparticle with surface alloying order is formed. Finally, surface melting occurs at growth temperatures higher than 900 K.