Ultimate Manipulation of Magnetic Moments in the Golden Tetrahedron Au20 with a Substitutional 3d Impurity

Nanocluster systems that are electronically stable and highly magnetic have been of intense research interest due to their potential as magnetic superatoms. In this study, we consider a more intriguing case of the unique golden pyramid with a substitutional 3d impurity. In particular, we investigate the geometry, stability, and magnetic properties of Au19M clusters (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) by means of density functional theory calculations. It is found that the structural patterns of doped species evolve from endohedrally doped cages to exohedrally doped tetrahedrons when M goes from Sc to Cu. The robustness of the Au20 unit tends to be retained in its tetrahedral doped counterparts. Remarkably, the quenched magnetic moment of Au20 increases in a systematic manner with the appearance of 3d impurities. We demonstrate that not only the interaction between the magnetic impurity and valence electrons of the Au host but also the itinerant behavior of the impurity valence states have been taken into account to understand the magnetism of Au19M clusters.