The structural, electronic and magnetic properties of Ga_8−xMn_xAs₈ clusters

We systematically investigate the ground-state magnetic properties of Ga_8−xMn_xAs₈ 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_8−xMn_xAs₈ 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_8−xMn_xAs₈ (x=4, 6, and 8), while Ga₈As₈ and Ga₆Mn₂As₈ are nonmagnetic. The possibility of multiple ground states of Ga_8−xMn_xAs₈ (x=4, 6, and 8) is also demonstrated. The binding energy and LUMO–HOMO gap analysis show that Ga_8−xMn_xAs₈ clusters with large x are more likely synthesized and exhibit stronger chemical reactivity. - Highlights: • The ground-state structural and magnetic configurations of Ga_8-xMn_xAs₈ clusters are predicted by using the particle swarm optimization (CALYPSO) code and fixed spin-moment method. • For the ground state and low-lying isomers of Ga_8−xMn_xAs₈ clusters, Mn atoms are gathered at the core of cluster, and ferrimagnetic Mn–Mn coupling is found. • Ga_8−xMn_xAs₈ with large x is more likely formed and reacts with each other to create larger clusters