First-principles study on the structure, electronic, and magnetic properties of Mn-doped (ZnS)12 clusters

A first-principles density functional investigation has been performed to evaluate the structural, electronic, and magnetic properties of (ZnS)12 clusters doped with one (monodoped) and two (bidoped) Mn atoms. Substitutional, endohedral, and exohedral doping are considered. The substitutional isomers are found to be most favorable in energy for both monodoped and bidoped clusters. For the optimized isomers of the monodoped case, the doping-induced changes of the bond lengths generally are less than 0.03 Å. The total magnetic moment is independent of atomic configuration. For the bidoped case, we find that the magnetic coupling between Mn atoms in host cluster depends on their local environment. The cohesion of substitutional bidoped isomers is found to be more sensitive to the magnetic coupling, while the exohedral ones are more sensitive to the chemical bonding. Most importantly, we demonstrate that the endohedral bidoped (ZnS)12 cluster favors the ferromagnetic state, which has potential applications in nanoscale quantum devices.