Abstract
In this study, we investigated characteristics of chemical mechanical polishing based on its structure and charge calculated by molecular dynamics simulations and first principles calculations. In the structure of 40% La-doped CeO2 (Ce0.6La0.4O1.8) nano cluster, the oxygen atoms hop between oxygen atom defects and diffuse from its surface to its center. Moreover, since oxygen deficiency state occurs on the surface of the cluster due to the oxygen atom diffusion, the Ce atoms on the surface are barely formed. According to the calculated charge of the cluster, the valence values of the Ce atoms on the surface decrease from +IV to +III after the oxygen atoms′ diffusion. When this Ce atom approaches to the bare oxygen atom on the SiO2 surface, the valence value of the Ce atom changes from +III to +IV, and the Si-O bond weakens due to the chemical reaction between the Ce atom and SiO2 surface. Therefore, the oxygen defects created by doped La atoms in the CeO2 nano cluster prompts the chemical mechanical polishing process.
