Adsorption and migration growth of the Ce, O, and F adatoms on the CeO2(111) surface: A density functional theory study

摘要

In order to investigate the microscopic behavior of the crystal surface growth of the fluorinated cerium dioxide polishing powder, the adsorption and migration of the Ce, O, and F atoms on the CeO2(111) surface were studied by using density functional theory with Hubbard correction +U.The adsorption energies of three single atoms at five high-symmetry sites and the migration activation energies along the migration pathway on the CeO2(111) surface were calculated. Results show that the most stable adsorption sites of the Ce, O, and F atoms were the O-h, Ce-bri, and Ce(t)sites, respectively. The Ce atom migrated from the O(h)to the O(t)site. The O atom migrated from the Ce(bri)to the O(bri)site. The F atom migrated from the Ce(t)to the O(h)site. The migration activation energies of the Ce, O, and F atoms along the migration pathways were 1.526, 0.597, and 0.263 eV, respectively. The F adatom does not change the spatial configuration of the Ce and the O atoms. When the O vacancy occurs on the CeO2(111) surface, the F adatom can make up for the O vacancy defect.