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Vicinal noble metal surfaces are suitable substrates for growing nanostructures with low-dimensional properties. Recently, Au vicinal surfaces like Au(23,23,21), Au(887), and Au(223) have been identified as suitable templates for growing 1D and 2D nanostructured solids. The Au(887) surfaces are made up of a uniform array of (111)-oriented terraces of comparatively large width (3.8 nm). The surface state has one dimensional character, i.e., it has a free-electron-like dispersion along the terraces and it becomes totally confined between two steps in the perpendicular direction. Moreover, the Co forms an ordered array of nanodots on Au(887) surface in the temperature range of 95 K to 170 K. The Co nanostructures have been grown on stepped Au(887) at 135 K and room temperature. The STM has been performed for Co nanodots grown at room temperature. Because the nanodots are formed at room temperature, the array does not have perfect long range ordering. Two kinds of dots co-exist on the surface. The high resolution angle-resolved photoemission experiments were performed as a function of Co coverage. For Au(887), we confirm the appearance of an intense one-dimensionally confined surface state on Au(887), which agrees with previously reported results. The angle resolved spectra obtained for 0.2 ML Co deposited on Au(887) at room temperature still shows quantization in the perpendicular direction and free-electron-like dispersion in the parallel direction. As the Co coverage is increased to 0.4 ML at room temperature, it becomes more difficult to discuss the behaviour of the surface state due to increasing Co 3d spectral weight, but the quantization of the surface state perpendicular to the step appears to become weaker. The lateral quantization of the surface state survives the formation of ordered Co nanodots of 0.2 and 0.4 ML at the optimum growth temperature of 140K. The Co 3d state of nanodots are probed by taking advantage of the Au 5d Cooper minimum, where the photoemission cross section of the substrate valence band is strongly reduced. The exchange splitting and magnetic interdot coupling has been investigated. Reports of a vanishing exchange splitting, by the Kawai group, at low coverages cannot be confirmed. |