Simulation studies on structural evolution of gold clusters during solidification

The thermal evolution and dynamic properties of gold clusters with different number of particles are investigated by the molecular dynamics simulation during the cooling process. A comparison between the solidification of bulk system and that of the clusters shows that the clusters of different sizes will form different microstructures under the same cooling condition. Clusters with the larger number of particles transform from liquid-like to crystal-like structure discontinuously. In the smaller clusters, no similar structural transformations are found. The microstructure transition in the cooling process of gold clusters is dependent on the number of particles. By the calculation of the mean square displacements (MSDs) of different clusters, it shows that the MSDs of clusters during solidification have a close correlation with the structural transition behaviors.