Methanethiolate structural phases on Cu{111} observed using a novel fibre-optic low-energy electron diffraction instrument

摘要

We have used a novel fibre-optic low-energy electron diffraction (FO-LEED) instrument, capable of low flux measurements that minimise electron beam damage to surface overlayers, to study methanethiolate (CH_3-S-) structural phases formed on Cu{111} at temperatures between 110 and 300 K. Three structural phases were seen: a (3~(1/2)×3~(1/2))R30° phase that forms at 110-140 K; a (4×4) phase which was observed transiently at 110 K; and a pseudo-{100} reconstructed phase which forms at room temperature. We discuss these in the context of previous studies of this system, and demonstrate the ability of the FO-LEED instrument to record high-quality LEED patterns and intensity data from a strongly beam-sensitive surface.