Geometries, electronic structures, and magnetism of small BimCon clusters

Geometries and electronic structures of BimCon (m ⩽ 18, n ⩽ 2) clusters are calculated within the framework of density-functional theory (DFT), indicating pattern growth, stability, magic number clusters, and magnetic moments. Pattern growth is amorphous and appears similar to the pure Bim and the other group-V elemental clusters. Co atoms always reside on the core or on the symmetry axis of the cluster; and tend to form three bonds with three Bi atoms. The structures' stability increases as the Co atoms are added into the Bim clusters. Magic number clusters are Bi2Co, Bi4Co, Bi6Co, Bi9Co, Bi10Co, Bi2Co2, Bi4Co2, and Bi7Co2. The magnetic moments of the BimCon clusters (m ⩽ 12, n ⩽ 2) derives mainly from the Co atoms and additional effects due to the chemical bonding with the Bi atoms in the clusters.