Growth of cobalt on the nanostructured Cu–CuO(1 1 0) surface

The growth of Co on the Cu–CuO stripe phase has been studied by means of scanning tunneling microscopy. Depositing submonolayer amounts of Co on the Cu–CuO stripe phase leads to the substitution of Cu atoms in the Cu–O rows. The expelled Cu either forms Cu islands on the bare Cu areas or is incorporated in Cu–Co–O compound structures similar to the ones observed for the fully oxygen covered Cu(1 1 0)-(2×1)O surface. In addition, narrow Cu–Co–O-bridges connecting neighboring CuO stripes are formed. With increasing Co coverage the CuO stripes are dissolved as the oxygen floats on top of the growing Co film. Nevertheless, the growing Co film replicates the Cu–CuO stripe phase periodicity. Due to the retarded growth on the bare Cu areas, holes are left in the Co film which are aligned into rows along the [0 0 1]-direction and located right above the former Cu stripes. During annealing these holes serve as segregation channels for Cu, which produces a Co–Cu–O surface compound on top of the Co film with a characteristic `(1×2)ʹ reconstruction.