Stability and magnetic properties of transition metal (V, Cr, Mn, and Fe) doped cobalt oxide clusters: a density functional theory investigation†

Co_n−1TMO_n−2⁺ (n = 6–8), (TM = V, Cr, Mn, and Fe) clusters are investigated using density functional theory calculations. The transition metal atoms preferentially replace one Co atom at sites where the number of metal–oxygen bonds is maximized, forming more stable structures. The evaporation of a Co atom is the most fragile dissociation channel for both pure and doped species. Bare cobalt oxide clusters exhibit parallel spin ordering, whereas both parallel and antiparallel spin ordering are observed in the doped species. Notably, a ferromagnetic-to-ferrimagnetic transition occurs in the V-doped clusters, while the ferromagnetic behavior is enhanced in the Fe-doped species.