The electronic and magnetic properties of MnScN (N=2-10) clusters

Mn-doped scandium clusters have been systematically investigated using the density-functional approach. It was found that, starting from N = 6, the growth patterns of the ground-state structures of MnScN clusters are dominated by octahedral structures with the Mn atom occupying the center of the host framework. The calculated results show that doping with Mn contributes to improving the stability of the scandium framework. The octahedral structure with the Mn atom occupying the center from N >= 6 has a relatively larger HOMO-LUMO gap compared with small-sized MnScN clusters. Also, the largest oscillation of the energy gap occurs at N = 5 and 6. Moreover, the local peaks of N = 3, 5 and 8 of the energy gap are in agreement with the second-order energy differences. The encapsulated Mn atom, coupled with the antiferromagnetic alignment with N >= 6, reduces the magnetism of the host Sc-N clusters in most cases. This is different from Mn doped into B-n, Ge-n, and Bi-n clusters. The MnSc6 cluster not only has the smallest energy gap (about 0.01 eV), but also the largest magnetic moment of 5 mu(B) of all of the MnScN clusters.