Abstract
The global structural optimisations for Ni–Al nanoalloy clusters at different compositions have been investigated using particle swarm optimisation combined with simulated annealing method. The second moment approximation of the tight binding potential has been used in describing the interatomic interactions. Some stable structures were obtained for NixAlx(x=1–8), Ni3xAlx(x=1–4) and NixAl3x(x=1–4) nanoalloy clusters. The simulation results show that the lowest energy isomers of nanoalloy clusters with the approximate composition 'NiAl, Ni3Al and NiAl3' generally have structures based on icosahedral packing. It is confirmed that segregation is favoured for Ni–Al nanoalloy clusters, with the surface becoming richer in Al and the core becoming richer in Ni.