MOLECULAR-DYNAMICS SIMULATION OF DEPOSITION PROCESS OF ULTRAFINE METAL PARTICLES ON MGO(100) SURFACE

The structure and dynamics of the MgO(100) substrate surface, Au clusters, and the deposition process of Au clusters on MgO(100) were investigated by using the molecular dynamics (MD) method and computer graphics (CG). The arrangement of atoms at the MgO(100) plane was almost the same as that in an MgO crystal, in agreement with experimental results. The Au atoms in the Au cluster moved considerably with time even at 300 K, and the movement of atoms became more evident with increasing temperature. In agreement with the mobility of the Au cluster and the MgO(100) plane, the shape of the Au cluster changed significantly during the deposition process of the Au cluster on the MgO(100) plane, while the position of Mg and 0 ions on the MgO(100) plane did not change significantly. The shape of the Au cluster after deposition also changed markedly with the interaction potential between Au and MgO. When the interaction is below 10% of Au-Au bond energy, the cluster is almost spherical to maintain the shape of the original cluster. When the interaction energy becomes stronger to approximately 20-50% of the Au-Au bond energy, the deposited AU32 cluster is almost hemispherical. The geometrical fit at the Au-MgO interface can also be seen in AU32-MgO(100) interface.