Stability of GaxAsx±4 gallium arsenide fullerenes

Abstract

We have investigated the atomic structure and stability of GaxAsx +/- 4 gallium arsenide fullerenes by using ab initio structure optimization, electronic structure, and molecular dynamics simulations. We found that the hollow gallium arsenide fullerenes are stable when the pentagon edges are shared to reduce the number of homonuclear bonds. We used the energetics, the energy gap in the electronic structure, and the response of the system to thermal excitations as indicators for the stability of the gallium arsenide fullerenes. We found that As-rich fullerenes are more likely to occur and a successful synthesis may involve using high As-2 partial pressure over the GaAs bulk target. The hollow gallium arsenide fullerenes show the signature of structural transformations beyond 500 K through the formation of Ga-Ga homonuclear bonds. Preventing inner Ga atoms to make bonds with each other may be a path for gallium arsenide fullerenes and hollow cages in general.