Chapter 1 introduces the basic principles of atom diffractometry and scattering from surfaces. I discuss the experimental and theoretical methods employed to determine the atom-surface interaction potential. In addition, a brief description of the apparatus and typical measurements are given. In Chapter 2, a new method is developed for determining the atom-surface interaction potential by interference effects. Based on a 0.5 ML Ni-Cu(100) surface, the helium interaction potential on an unreconstructed Ni(100) overlayer is determined experimentally, which would not have been previously possible due to the absence of diffractive and resonant scattering intensity. A detailed investigation of growth mechanism and surface structure of Ni-Cu(100) is presented in Chapter 3. It is observed that the nickel growth occurs by forming ordered overlayer structures at and below room-temperature, whilst proceeds via alloying processes at high temperatures. The second growth system, Li-Cu(100), is studied in Chapter 4. A sequence of ordered overlayer structures with unusual electronic corrugations are observed in the growth at low temperatures. The surface corrugation for helium scattering from a complex structure, <i>c</i>(5V 2 x v 2)<i>R</i>45° Li-Cu (100), is derived through a diffraction analysis using the exact, close-coupled channels method. Finally, a comparison between neon and helium scattering from an ordered <i>c</i>(2x2) Li-Cu(100) structure is presented in Chapter 5. The surface corrugation for neon scattering is determined on a metallic overlayer for the first time. it is found that the neon corrugation amplitude is at least one order of magnitude larger than for helium. Such a difference exceeds those observed previously on low-index transition metal surfaces.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:604697 |
| Date | January 2006 |
| Creators | Huang, C. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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