Density-functional study of Au-Cu binary clusters of small size (n=6): Effect of structure on electronic properties

Abstract

We have carried out DFT studies on the Au-Cu binary clusters of size n=6 with a view of studying the electronic property variation with changing structure and composition in these alloys. The Au-6, Cu-6 and the binary clusters (with the formula AuxCu6-x, x=1-5) minimize to triangular structures. Properties like the dipole moments show an interesting trend in these structures. With increasing Cu content these binary clusters prefer to minimize to a structure with a larger dipole moment and with increasing An content the minimized structures prefer An at locations that yield a smaller dipole moment. Deforming the structures to W-shape shows a red shift of the absorption maxima compared to the planar structures. The 'cap' shape and the 'W'-shape structures are of higher energy. (c) 2006 Elsevier B.V. All rights reserved.