Ag as a surfactant for Co/MgO(111)-(3×3)R 30°

Ag was examined as a potential surfactant to aid in the growth of smooth Co films deposited on MgO. Ag was deposited onto single-crystal MgO(111)-(3×3)R30° substrates. It was found that Ag formed islands upon annealing. Monolayer films of Co were subsequently deposited using an electrostatic electron-beam evaporator on single-crystal MgO(111)-(3×3)R30° substrates with 0.5–10 monolayers of Ag. The Ag/MgO substrates were held at room temperature or 450 °C during growth, with subsequent annealing of temperatures 400–800 °C. These films have been characterized using low-energy electron diffraction, x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Despite the fact that Ag formed islands, it was found that the presence of Ag did have a surfactant effect upon the thin-film growth of Co on Ag/MgO(111)-(3×3)R30°. Co islands were still present, but the surface was much smoother than for films grown without the Ag surfactant. XPS peak intensity changes and AFM suggest strongly that Ag segre...