Small bimetallic clusters Agn-1M (M = Au, Co, Cu, Ni, Pd, Pt; n=3, 9, 15): Density functional theory and genetic algorithm*

We investigated the effect of size and composition on the properties of bimetallic nanoclusters. The geometric structures, stabilities, and electronic properties of size-selected Agn-1M (M = Au, Co, Cu, Ni, Pd, Pt; n = 3, 9, 15) bimetallic nanoclusters are systematically analyzed using spin-polarized density functional theory (DFT) within the generalized gradient approximation (GGA). We determine the most stable geometries for these clusters using a genetic algorithm (GA) in combination with DFT. Our results show that doping pure silver clusters with an M atom (transition metal), referred to as a guest atom, increases the stability as compared to pure Agn (n = 3, 9, 15) clusters. The results for various properties including formation energy per atom, electronic structure, magnetic moments, and vibrational density of states (VDOS) are evaluated as a function of both size and composition of the system. The adsorption of selected bimetallic clusters on hydroxylated alumina substrate shows weak binding and minor changes in geometric properties except for Ag8Pt.

Automated summary

In this study, the effect of size and composition on the properties of bimetallic nanoclusters was investigated. The geometric structures, stabilities, and electronic properties of Agn-1M (M = Au, Co, Cu, Ni, Pd, Pt; n = 3, 9, 15) nanoclusters were analyzed using spin-polarized density functional theory within the generalized gradient approximation. The results showed that doping pure silver clusters with a transition metal atom improved their stability. The properties including formation energy, electronic structure, magnetic moments, and vibrational density of states were evaluated as a function of size and composition. Weak binding and minor geometric changes were observed for the adsorption of selected bimetallic clusters on a hydroxylated alumina substrate, except for Ag8Pt.