Theoretical and experimental studies of the structures of 12-, 13-, and 14-atom bimetallic nickel/aluminum clusters

The structures of Ni(n)Al(p) clusters of all compositions with n+p=12, 13, and 14 are studied both experimentally and theoretically. Experimental reactions of the clusters with N(2) are used to determine the number of Ni atoms residing in the cluster surfaces. In agreement with the theoretical predictions, the N(2) saturation levels are consistent with clusters having icosahedral and icosahedral-based structures. The various N(2) adsorption channels seen in the experiment are explained in terms of the computed composition-dependent patterns of the configurational energies of the different structural forms. (C) 2002 American Institute of Physics.