Interpretation of a Complex Low Energy Electron Diffraction Pattern: Carbonaceous and Sulphur-containing Structures on Ni(111)

摘要: THE complex low energy electron diffraction pattern shown in Fig. 1, previously described tentatively as Ni(111) (16√(3)×16√(3)) R 30°—C (ref. 1), has been observed during an investigation of the reactions with various carbon or sulphur-containing gases, including ethylene, monoxide1, benzene and hydrogen sulphide. The is produced at a variety surface temperatures, depending on reactant, from 20° to 350° C exposure times 10 1,000 Langmuirs (L=10−6 torr s). patterns are not identical every case but consistent geometrically grouping beams into two distinct levels intensity. strong features predominate 70 V above; weaker spots more clearly seen lower voltages (Fig. 2). differences between obtained different reactants relative intensities within each category. Both 1 2 products reaction ethylene. action H2S series patterns, one which was pattern, diffuse complicated by presence traces succeeding patterns. same characteristic were undoubtedly present, however.