Evaluation of endohedral doping of hydrogenated Si fullerenes as a route to magnetic Si building blocks

Abstract

Density-functional theory based global geometry optimization is used to scrutinize the possibility of endohedral doping of hydrogenated Si fullerenes as a route to Si nanostructures with high magnetic moments. In contrast to previous suggestions, our unbiased sampling finds the smallest Si 16H 16 endohedral cage generally too small to encapsulate 3d metal dopant atoms. For the next larger fullerene-like cage, however, we identify perfectly symmetric M@Si 20H 20 (M=Co, Ti, V, and Cr) cage structures as ground states. These structures conserve the high spin moment of the dopant atom and therewith underscore the potential of this Si nanoform for novel cluster-based materials with unique magnetic properties.