Electron reflectivity measurements of Ag adatom concentrations on W(110)

The density of two-dimensional Ag adatom gases on W(110) is determined by monitoring local electron reflectivity using low energy electron microscopy (LEEM). This method of adatom concentration measurement can detect changes in adatom density at least as small as 10$^{-3}$ ML for a $\mu$m size region of the surface. Using this technique at high temperatures, we measure the sublimation rates of Ag adatoms on W(110). At lower temperatures, where Ag adatoms condense into monolayer islands, we determine the temperature dependence of the density of adatoms coexisting with this condensed phase and compare it with previous estimates.Comment: Presented at the ECOSS 23 Conference (Berlin 2005

THE IMPORTANCE OF INDIRECT INTERACTIONS BETWEEN ADATOMS FOR TEMPERATURE DEPENDENT PROCESSES ON METAL SURFACE*

The asymptotic form of the indirect pseudopotential interaction of noble metal adatoms on jelfium is used to interpret the phenomena arising during thermal treatment of the noble metal submonolayers on W(110). It is shown that the 2D condensation is an activated process. The growth of open clusters needs lower activation energy than the close-packed island formation. Therefore the open clusters should predominate at low temperatures and low coverages, as it is observed experimentally. On the basis of calculation of the total energy of submonolayers as a function of coverage Θ the experimental measurement of desorption energy vs. coverage is discussed

Structure and perpendicular magnetization of Fe/Ni(111) bilayers on W(110)

Scanning tunneling microscopy and low energy electron diffraction show that high quality fcc Ni(111) films can be prepared on W(110). The subsequent coverage of this Ni template by monolayers of Fe leads to a Fe/Ni bilayer with striking magnetic properties. The Fe cap layer induces a spin reorientation of the easy axis of magnetization from in-plane to perpendicular to the film, as checked with the magneto-optic Kerr effect. At higher Fe coverages, an in-plane magnetization of the bilayer is found, which is proposed to be caused by the fcc to bcc transition in the Fe layer