The coadsorption of dissimilar metals, Mg and Bi, on Cu(0 0 1) at room temperature was studied using low energy electron diffraction (LEED). Five LEED patterns were observed at various coverages: c(2 × 2), c( 4√2 × 2√2)R45°, c(6 × 4), c(6 × 6) and p(4 × 4). The c(2 × 2) structure was determined by a tensor LEED analysis. Mg atoms substitute for every second Cu atom in the top layer, and Bi atoms are located at the on-top sites of the remaining surface Cu atoms. The structure parameters demonstrate that Bi atoms pull up Mg atoms located in the substitutional sites, indicating a direct, attractive interaction between coadsorbates. Reasons for the formation of the c(2 × 2) structure are discussed in comparison with the surface structures formed by the individual adsorption of Mg and Bi.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry