Scanning tunneling microscopy study of the reaction of Br2 with Cu(100)

摘要: The adsorption of Br2 on Cu(100) and the further reaction with to form CuBr was studied using scanning tunneling microscopy (STM). Although low energy electron diffraction indicated formation a c(2 × 2) layer immediately upon dissociative Br2, thermal fluctuations in adsorbed prevented this structure from being observed until coverage exceeded roughly 80% saturation. As saturated, substrate steps were rotate align parallel 〈100〉 close-packed directions adlayer. rotated exhibited that STM movies showed due kink diffusion. Further exposure greatly decreased step resulted bulk CuBr. former density allowed more Br atoms be accommodated layer. predominant source Cu for progressed receded they reached another formed {110} facet. Defects such as kinks domain boundaries not contribute significantly reactivity steps. at uniform; certain segments found far reactive than others. Annealing increased lengths segments, consistent previous temperature programmed desorption data annealing increases surface. Comparison images unreactive sections suggested variation is thermally driven relaxation atomic positions around step. mobile aggregated into clusters locations no obvious correlation changes surface associated consumption implications these results oxidation etching reactions metal surfaces are discussed.