Structure of binary clusters: are icosahedra relevant ?

Abstract

We investigate the structure of 13-particle clusters in binary alloys for various size ratios and different concentrations via MD simulation. Our goal is to predict which systems are likely to form local icosahedral structures when rapidly supercooled from the melt. We calculate the energy spectrum of the minimal energy structures, and characterize all detected minima from both their relative probability and from a structural point of view. We identify regions in our parameter space where the icosahedral structure is dominant (like in the corresponding monoatomic case), regions where the icosahedral structure disappears and other where icosahedral structures are present but not dominant. Finally, we compare our results with simulations reported in literature and performed on extended binary systems with various size ratios and at different concentration