MAGNETISM IN SMALL VANADIUM CLUSTERS

Using the self-consistent-field molecular-orbital theory and the density-functional approximation, we show that vanadium could become magnetic if its size and dimension were constrained. This is illustrated for vanadium forming clusters with body-centered-cubic (bcc) geometry as well as for linear chains. The magnetic moment of the bcc clusters is found to vanish abruptly as the size increases, while the clusters always retain their moment in the linear-chain configurations. The moments are also found to be finite for large interatomic spacings irrespective of the cluster topology, and tend to vanish when the interatomic distances are reduced. The results are explained by using a simple Stoner criterion.