Domain structure, segregation and morphology of the Pt3Sn(111) surface

Abstract Using spot-profile analysis low-energy electron diffraction, we have studied the domain structure and morphology of the Pt 3 Sn(111) surface after sputtering at room temperature and subsequent anneal treatments which result in the formation of the previously reported ( 3 × 3 ) R30° and (2×2) structures. In addition, we present new results on the temperature-dependent composition of the outermost layer and the subsurface region that is obtained from quantitative analysis of low-energy ion scattering and Auger electron spectroscopy experiments. The combination of these results and previous experiments yields a detailed picture of the evolution of the surface region during the anneal treatments. Finally, we propose the existence of a phase transition at high temperatures between the (2×2) phase and a (2×2)′ phase (not previously observed) on the basis of reversible changes in the SPA–LEED, LEIS and AES data.