Surface-induced magnetism in Au particles/clusters

Magnetic properties of Au particles/clusters with different sizes and different shapes were investigated. It is found that magnetic behaviors of Au particles/clusters are strongly influenced by their morphology. The 25nm Au particles annealed at 700°C for 5h show a big change in shape with a much greater surface than that of 5nm Au particles, or 25nm particles without annealing, and as a result, magnetism was induced. It suggests that surface effect can play a key role in tailoring magnetic properties of Au particles/clusters.