Effect of Rare-Earth (RE) atom doping on ultra-small gold clusters: REAu_n (RE: La – Lu; n = 1 – 5)

Pure and doped ultra-small gold (Au_n) clusters have been the subject of numerous studies due to their novel structural, electronic, and catalytic properties. However, a comprehensive analysis of rare-earth (RE) atom-doped Au_n clusters, with their potential applications in linear and nonlinear photonics, is limited.

Here, we present our recent results from a density functional theory (DFT) study focusing on the geometries, electronic, and magnetic properties of REAu_n (RE = La – Lu; n = 1 - 5) clusters. Our calculations predict that the RE atom stabilizes the Au_n cluster by maximizing the RE-Au bonds. While the REAu_n (n = 1 – 4) clusters prefer planar geometries, a close competition between planar and non-planar structures was seen at n = 5. In most REAu₅ clusters, non-planar structure is energetically favored, while a distinct preference for the planarity is predicted for REAu₅ (RE = Eu, Tb, Tm, and Yb). The bonding analysis of REAu₅ revealed the dominance of the RE-d orbitals in the formation of frontier molecular orbitals. The spin magnetic moments of the REAu_n clusters show that the dopant RE atoms retain their atomic spin magnetic moments.

This work was supported, in part, by the NSF S-STEM Scholarship (Award #2028230) and the West Chester University SURI program.