High-moment films produced by assembling nanoclusters

We have used X-ray magnetic circular dichroism to determine the orbital and spin moments in exposed and embedded mass-selected Fe nanoclusters (250-550 atoms) deposited in situ using a gas aggregation source. The isolated and exposed particles have a total moment that increases with decreasing cluster size and reaches 2.4 μ_B in 250-atom clusters. Although this is enhanced relative to the bulk, it is smaller than found in free clusters of the same size. Coating the exposed clusters with Co, however, increases the spin moment to 2.6 μ_B. The prospects for producing high-moment materials by cluster assembly are discussed.