Growth phases and optical anisotropy of Co on preoxidized Cu(110) -: art. no. 184424

We investigate the growth of Co on Cu(110) surfaces using oxygen as a surfactant. Reflectance anisotropy spectroscopy (RAS) and scanning tunneling microscopy (STM) were used for in situ analysis during different stages of growth. STM images taken after growth interruptions at various Co coverage exhibit a nearly laver-by-layer growth of up to 20 ML. For submonolayer coverage, different Co-Cu-O-phases are found, in agreement with previous work. Above monolayer coverage we observe a fairly smooth Co layer with an oxygen-terminated Co(110) (3 x 1) surface structure. RAS spectra taken during growth interruptions reveal characteristic fingerprint-like spectra assigned to the different growth phases. We interpret the features of the RAS spectra in terms of surface-state- and bulk-related electronic transitions. Moreover, we show that real-time monitoring of the growth process is possible by taking RAS transients at a fixed photon energy.