Geometries, stability and dissociation behavior of AgnCo clusters (n = 1-12): A theoretical investigation

Abstract

The geometric structure, stability, dissociation channel and magnetism of AgnCo clusters (n = 1–12) have been studied using density functional theory. The results show that the Co atom tends to choose the highest coordination position. The ground state of AgnCo clusters prefers the planar motif at small sizes (n less than 4) but favors 3D structures at larger sizes (n = 5–12). The stability of clusters is not only governed by the symmetric geometry but also strongly depends on the electronic structure and the filling rule of the electron shells. The Ag9Co cluster with 18 valence electrons fully filled the electronic shell (1S21P63dCo10), which is considered as a potential superatom. The total magnetic moment of AgnCo clusters is governed by the electron localization on the Co atom. The relative stability of the clusters is determined by the average binding energy, the second-order difference energies, and the dissociation energies.