Role of steps in CuO formation on Cu(410) using a hyperthermal O molecular beam

Okada, Michio*; Vattuone, L.*; Moritani, Kosuke*; Gerbi, A.*; Savio, L.*; Yoshigoe, Akitaka ; Teraoka, Yuden; Rocca, M.*; Kasai, Toshio*

It is important to make clear oxidation processes of Cu from an industrial view point because cupper oxides are candidates of high-Tc super conductor and solar cells. However, the details of the chemical reaction dynamics for the Cu oxidation processes have not been understood yet. We have already studied initial oxidation processes of Cu(100) and Cu(110) surfaces by using supersonic oxygen molecular beams. In this research, effects of surface defects for the surface oxidation are investigated by using the Cu(410) surface with large step density. It was found that oxidation rate of the Cu(410) surface was larger than Cu(100) surface, but, smaller than Cu(110) surface in the oxygen coverage range larger than 0.5 monolayer, from which formation of CuO was observed. The phenomenon can be understood from the fact that the (410) surface consists of (100) terraces and (110) steps.