Total target currents for grazing scattering of keV protons from a crystal target are used to investigate the structure of surfaces and ultrathin films. This current shows pronounced maxima whenever the azimuthal incidence angle coincides with close-packed rows of atoms in the surface and subsurface layers. The real-space method is applied to study monolayer and bilayer films of Mn and of CoMn epitaxially grown on a Cu(001) surface.

The structure and magnetism of ultrathin Fe films epitaxially grown on a Cu(001) surface are investigated by grazing scattering of fast H and He atoms or ions. By making use of a new variant of ion beam triangulation based on the detection of the number of emitted electrons, we obtain direct information on the structure of the film surface. We observe for room temperature growth a dominant and defined fcc-like structure. Complex surface reconstructions as reported in recent STM and LEED studies are observed only for cooling and H2 dosing.

We present a combined theoretical and experimental study of island nucleation and growth in the deposition of Co on Cu(001) -a prototype for understanding heteroepitaxial growth involving intermixing. Experimentally, ion scattering is employed. Using density-functional theory, we obtain energy barriers for the various elementary processes and incorporate these into a kinetic Monte Carlo program to simulate the heteroepitaxial growth. Both the simulations and the experiments show a unique N-shape dependence of the island density on temperature that stems from the interplay and competition of the different processes involved. DOI: 10.1103/PhysRevLett.90.076101 PACS numbers: 68.55.-a, 61.43.Hv, 68.35.Fx, 82.40.Bj Heteroepitaxial metallic structures, such as Co=Cu multilayers represent a new material that has high potential for the development of magnetoelectronic devices. In order to control the interfacial properties it is important to achieve a quantitative understanding of the morphology that develops during growth and its dependence on the growth conditions. A standard model for the initial stages of growth is given by nucleation theory [1], where the island density n x is expressed in terms of the deposition rate F, the adatom hopping rate D D 0 exp ÿE d =k B T , and the binding energy E b of the critical nucleus of size i,The linear dependence of lnn x on 1=T is widely used to deduce quantities such as activation barriers from islanddensity measurements, when adatoms form islands on top of the substrate [2]. However, in heteroepitaxial systems, deposited atoms may incorporate into the substrate displacing substrate atoms into the growing layer [3][4][5][6][7][8][9]. The effect of site exchange is not considered in Eq. (1). A prototypical system where intermixing takes place is Co on Cu(001). A broad [5,6] and bimodal [6] island-size distribution was observed in submonolayer growth studies using scanning-tunnelling microscopy (STM) -in contrast to a Poisson-like distribution anticipated in standard nucleation theory [1]. In addition Nouvertné et al. reported that the island density at 415 K is slightly higher than at 295 K [6], which is at variance with the predictions of Eq. (1). The island composition was found to depend on the growth conditions and to vary from mostly Co to mostly Cu. Moreover, a correlation has been observed between island composition and island size [5,6].From a fundamental standpoint, it is important to extend nucleation theories to account for intermixing. However, to date, only a few studies have attempted this [4,10 -13]. Chambliss and Johnson proposed that substitutional Fe atoms constitute stable nuclei for the growth of Fe on Cu(001) [4]. By accounting for monomer stability [i 0 in Eq. (1)] at substitutional Fe pinning sites, they found that the island density is independent of F=D. Meyer and Behm assumed irreversible pinning of adatoms at substitutional nucleation centers and found that the island density goes through a minimum with increasing temperature -consistent with that...

The magnetization reversal of ultrathin Co films on Cu(001) has been investigated by grazing ion scattering and magneto-optical Kerr effect. Differences in the behavior of surface and bulk magnetization are found and attributed to the reduced coordination and site symmetry at the surface. The reversal behavior of the surface magnetization depends on the chemical surface composition. For pure Co films, the reversal of the bulk magnetization is preceded by a complete reversal of the surface magnetization. A particular magnetic state of the surface is suggested as a precursor for magnetization reversal.

The properties of electroless films produced from a bath designed for horizontal plating, the preferred technology for high production volumes in printed circuit board metallization, are reported. Film thickness, substrate type and electrolyte temperature were varied. Formation of a continuous layer of copper film is correlated with a change in the visual and spectroscopic appearance. Grain orientation is random in thin films and a 〈110〉 texture develops with increasing thickness. The plating solution contains Cu and Ni ions. Nickel co-deposits in copper films in the form of Ni hydroxide, and its concentration decreases from about 6% in the vicinity of the substrate to about 1% at the film surface. Film stress and strain were measured by substrate curvature and X-ray diffraction, respectively. Both stress and strain decrease as the film thickness increases. Stress remains tensile throughout during deposition and during relaxation, promoting film adhesion by preventing blisters. After deposition, stress relaxes first towards compressive and then towards tensile. The stress, the stress relaxation and the Ni concentration are high at the base of the film. We attribute this to the higher volume fraction of grain boundaries (smaller grain size) in this region.