The correlation of surface topography with the growth of metal thin films is reviewed. UHV-cleaved surfaces of ionic crystals such as NaCl, KCl, KBr, and MgO have fine structures distinguished in six characteristic zones : (1) Starting zone; (2) V-zone; (3) transition zone; (4) tartan zone; (5) stop-band zone; (6) restarting zone. Epitaxy, non-epitaxy, and graphoepitaxy of Sn are strongly influenced by these surface zones of the NaCl and KCl substrates. In the case of Au films, structural changes as well as morphological changes occur at the steps of the NaCl substrate. In addition, for Au/NaCl, quantitative results by the discrete variational Xα cluster method are indicated. On the other hand, the graphoepitaxy proposed first by H.I. Smith and co-workers is characterized by “epitaxial” growth on amorphous substrates having artificially produced surface-relief structures. Some experiments concerning graphoepitaxy are introduced.
A summary is given of Langmuir-Blodgett (LB) films, which are ultrathin organic films with controllable structures of molecular dimensions. The preparation techniques, both fundamental and advanced, are reviewed so that the characteristic features of LB films can be understood. The recent trends towards applications in electronics are also outlined, together with the historical background. It is shown that the recent “boom” in LB films represents in reality an advanced stage which has been attained after a period that is longer than the decades of fundamental studies.
The surface fluorination of graphite in some glow discharge plasmas was studied. The plasmas contained excited fluorine atoms, and were, generated by various discharges, Direct-Current, Radio-Frequency (13.56MHz) and Micro-Wave (2450MHz), with CF4 as source gas. The contact angles formed by water, dropped on the treated surfaces, were over 160°, and changes of mass indicated addition of the fluorine. But the effect of etching appeared as a decrease of mass under some conditions, and such effects were observed also by a scanning electron microscope. The ESCA results on the surfaces treated by plasma were similar to those which were measured on the surfaces treated by F2 gas at high temperature.
A device for inverse photoemission spectroscopy using a personal computer was made. An energy selective Geiger-Muller photon counter was employed and its resolution was 0.7eV. The operating frequency was programable, which made it easier to optimize the pulsed operation of the accelerating voltage and of the filament heating. This system was applied to the measurement of the density of unoccupied states above the Fermi level for Ni (100) surface. The unoccupied states of the Ni 3d band were clearly observed with high resolution.
Studies of material surfaces interacting with plasma have been recognized to have played a very important role in the development of nuclear fusion devices. Particularly, in the large tokamak devices which have been recently built, serious damages on the first wall surface have been observed due to plasma disruption and unipolar arcing which caused sputtering, evaporation, melting and so on. Therefore, elementary processes of plasma wall interactions taking place in the actual torus devices have to be understood urgently, and then efforts have to be taken to radiation damages from both the plasma and material points of view. This review describes the major problems and the approaching methods of such studies in plasma wall interactions, and the specific recent problems caused by non-steady state plasma in the large tokamak devices.
Recent theory of the resonant electron transfer in atom scattering from a metal surface is reviewed with emphasis of the limiting formulae which give simple physical interpretations. The atom is assumed to follow a given classical trajectory. The electronic system is treated quantum-mechanically within the wide band approximation for the metal conduction band, since the motion of the atom is assumed to be slow. For the charge exchange problem, the electron correlation is incorporated into the theory within the Hartree-Fock approximation. Only low-lying electron-hole pair excitations are accounted for as the energy dissipation channel.
Car body corrosion in North America and Canada caused by de-icing salt is classified into cosmetic corrosion and perforation. The cosmetic corrosion starts from paint defects or damages of the outer panel, and brings about rust formation and paint exfoliation. It can well be simulated by a cyclic corrosion test (CCT), which is a combination of salt spray, drying, humidifying and freezing. Zinc plated sheet exhibits much better performance in CCT than cold sheet, although it gives a poor paint adhesion in salt spray test (SST). There is a difference of the underfilm corrosion mechanism between CCT and SST. Nowadays several types of zinc coated steel are widely used for car body.