INVESTIGATION OF THE GROWTH OF CO ON CU(111) AND SB CU(111) USING PHOTOELECTRON FORWARD SCATTERING/

We recorded the angular anisotropies of photoelectron intensities aris ing from thin Co layers on a clean and Sb-covered Cu(111) surface. For ward scattering leads to intensity enhancements along close-packed dir ections and thus, the azimuthal distributions reveal information about the mode of heteroepitaxial growth. For Co on the clean Cu surface we find evidence for the formation of three-dimensional islands even at low Co coverages. At about a nominal coverage of 4 ML, the Co layer un dergoes a structural transition from fee to hcp stacking which can be easily identified by means of symmetry of the angular distributions. T he influence of Sb as a surfactant on the growth behaviour has also be en studied. Showing the typical effect of segregating to the surface, Sb induces the Co film to grow in a rather flat manner. Accordingly, t he fcc --> hcp transition is delayed to a nominal Co coverage beyond 1 0 ML.