Reconstruction of Cu(111) induced by a hyperthermal oxygen molecular beam

Moritani, Kosuke*; Okada, Michio*; Teraoka, Yuden; Yoshigoe, Akitaka ; Kasai, Toshio*

This paper reports a study on the reconstruction at Cu(111) surface induced by a hyperthermal oxygen molecular beam (HOMB) at room temperature. The HOMB incidence at translational energies larger than 0.5 eV induced surface reconstruction in the oxygen coverage larger than 0.27 ML. On the other hand, long-range-ordered structures were not formed even at the oxygen coverage of 0.4 ML for the backfilling of thermal O at room temperature. The O1s XPS peak for the HOMB incidence at room temperature was resolved into two components, 529.4 and 528.9 eV, at the oxygen coverage larger than 0.27 ML, which can be assigned to the O atoms occupying the threefold hollow sites on the unreconstructed Cu(111) surface and four-coordinated sites on the reconstructed structure, respectively. Annealing the reconstructed surface at 620 K decreased the oxygen coverage to 0.27 ML and induced so-called "29" superstructure.