The structural, electronic and magnetic properties of Ga sub(8-x)Mn sub(x)As sub(8) clusters

We systematically investigate the ground-state magnetic properties of Ga sub(8-x)Mn sub(x)As sub(8) clusters (x=0, 2, 4, 6, and 8) within the framework of density functional theory (DFT) using a strategy that successively adopts the particle swarm optimization (CALYPSO) code and fixed spin-moment (FSM) method. The results show that for Ga sub(8-x)Mn sub(x) As sub(8) in the ground states or low-lying isomers, Mn atoms tend to assemble at the core of the clusters and the ferrimagnetic Mn-Mn couplings are identified for Ga sub(8-x)Mn sub(x)As sub(8) (x=4, 6, and 8), while Ga sub(8)As sub(8) and Ga sub(6)Mn sub(2)As sub(8) are nonmagnetic. The possibility of multiple ground states of Ga sub(8-x)Mn sub(x)As sub(8) (x=4, 6, and 8) is also demonstrated. The binding energy and LUMO-HOMO gap analysis show that Ga sub(8-x)Mn sub(x)As sub(8) clusters with large x are more likely synthesized and exhibit stronger chemical reactivity.