An Atom in a Golden Ring: M@Au$_{6 }$(M = Ti, V, Cr)

The electronic structure and magnetic properties in a series of transition metal doped Au clusters, MAu$_{6}^{-}$ (M = Ti, V, Cr), are investigated experimentally using photoelectron spectroscopy (PES) and density functional calculations. PES features due to the impurity atoms and the Au$_{6}$ host are clearly observed. It is found that all the MAu$_{6}^{-}$ and MAu$_{6}$ clusters possess a planar structure, in which the transition metal atom is located in the center of an Au$_{6}$ ring and carries large magnetic moments (2, 3, and 4 $\mu _{b}$ for MAu$_{6}$, M = Ti, V, and Cr, respectively).