Dimer Growth, Structural Transition, and Antiferromagnetic Ordering of Small Chromium Clusters

The evolution of structural and magnetic properties of small chromium clusters towards the bulk is elucidated through a systematic density functional study. A tightly bound Cr₂ dimer is found to play a key role in determining the cluster structures. A unique dimer growth route is discovered for clusters up to Cr₁₁, at which a structural transition occurs from the dimer growth to a bulklike body-centered-cubic structure. All the clusters exhibit antiferromagnetic ordering with size-dependent magnetic moments.