Structural, Electronic, and Magnetic Properties of Bimetallic Ni m Nb n (m plus n ≤ 8) Clusters: First Principle Study

Structural, electronic, and magnetic properties of bimetallic Ni (m) Nb (n) (m + nae<currency>8) clusters have been investigated using the particle swarm optimization coupled with density functional theory. Ninety-seven stable structures of Ni (m) Nb (n) clusters were found. Among these Ni (m) Nb (n) clusters, most of the ground state of bimetallic clusters prefers compact structures when m + n > 3. The HOMO-LUMO gaps of these bimetallic Ni (m) Nb (n) clusters were found in the range of 0.1-0.5 eV. The exchange splitting exists in most of these binary clusters and results in non-zero magnetization in these clusters. Most of the clusters show their magnetic moment strongly depending on the size, the symmetry, the configuration, and the composition. An interesting finding is that the magnetic moment per atom in NiNb and Ni2Nb clusters shows a larger value (i.e., 1.5 and 1.0 mu (B)) than that of the corresponding size of pure Ni clusters.