Influence mechanisms of the surface morphologies on the elementary diffusion kinetics on the Cu (1 1 0) surface

DFT calculations are performed to evaluate the energy barriers of the relevant elementary processes for the Cu and O adatoms on various morphologies of the Cu (1 1 0) surface. The diffusion paths of Cu and O adatoms and Cu–O units on clean, chain-added, step, and reconstruction surface are considered. Individual Cu and O atoms can diffuse in any direction with low barriers on clean Cu (1 1 0) surface. However, the move barriers for short Cu–O units are as high as 0.6–0.8 eV. The Cu–O units diffusion is made energetically possible with the presence of -Cu–O- chain on the surface and they prefer to stay away from the chain due to the repulsion. The barriers for the O atom diffusion near the step edge are calculated to be ~0.50 eV which are higher than that on the clean surface, and this ascribes to the strong adsorption of the step edge for O atoms. Additionally, O adatom diffuses on the (2 × 1)-O phase with a barrier of 0.968 eV, consistent with the experimentally observed reconstruction formation temperature.