QUANTIFICATION OF THE COMPOSITION OF ALLOY AND OXIDE SURFACES USING LOW-ENERGY ION-SCATTERING

The influence of the chemical environment on the low-energy ion scatte ring (LEIS) intensities from aluminum and nickel is investigated by st udying a number of different alloys (Ag80Al20, Ni80Pt20, NiAl{110}) an d oxides (gamma-Al2O3, alpha-Al2O3, alpha-Al2O3 sapphire {1102BAR), Ni O, 14 wt % Ni/gamma-Al2O3). The neutralization behavior of the He ions scattered from Al and Ni in alloys was found to be the same as for th e metals. Even for the oxides, where the chemical environment of Al an d Ni is radically different from that of the pure metals, the scattere d ion fractions are unaffected. For NiAl{110}, however, He ions scatte red from Al in the alloy show a significant lower neutralization proba bility in comparison to the pure Al. This was attributed to the differ ence in chemical environment. It will be shown that the influence of s urface roughness on the LEIS-signal intensity can be quantified. Furth ermore, this influence can be neglected when comparing pressed powders having different surface morphologies.