STUDY OF ALPHA-CU0.82AL0.18(100) USING LOW-ENERGY ION-SCATTERING

The clean alpha-Cu0.82Al0.18(100) surface has been investigated using low energy ion scattering. The surface structure was found to be simil ar to the structure of the Cu(100) surface. By measuring the first lay er concentration of Al using He+ and Ne+ beams and standard calibratio n procedure, the alpha-C0.82Al0.18(100) surface was found to be slight ly Al-rich. Analysis of multiple scattering of ions suggests that Al a toms do not form islands. It was also found that Al atoms sit higher t han the Cu atoms on the surface. By comparison with computer simulatio ns (SABRE and FAN2D), the buckling of Al was found to be 0.16+/-0.07 A ngstrom. No reconstructions were observed on the surface by low energy ion scattering which is in agreement with previous LEED studies.