Size dependent melting mechanisms of iron nanoclusters

Molecular dynamics simulations were used to study the change in the mechanism of iron cluster melting with increasing cluster size. Melting of smaller clusters (e.g., Fe55 and Fe100) occurs over a large temperature interval where the phase of the cluster repeatedly oscillates between liquid and solid. In contrast, larger clusters (e.g., Fe300) have sharper melting points with surface melting preceding bulk melting. The importance of the simulation time, the force field and the definition of cluster melting is also discussed.