Indium Substrate Research Articles

Electron beam effects in AES studies of micron size insulating particles

The problems associated with the Auger electron analysis of individual nonconducting 10–30 μ m sized particles isolated on an indium substrate are discussed. When low electron current densities are used, many of the particles studied charge in an uneven manner across their surface, preventing analysis. The observation that this charging effect can be largely removed or quantified by using higher electron beam current densities is described, and a based on the thermal effects of the electron beam on the particle is proposed. Care must be taken to prevent the electron beam from inducing secondary effects. However, it is often possible to be these higher electron density beams to differentiat between Auger peaks from the particles and those from the indium substrate.particles, incomplete and/or incorrect assignment of the surface species and their concentration could be made.

Electron mean-free pathlengths through monolayers of cadmium arachidate

The inelastic mean-free pathlengths λ, of 1042–1402 eV electrons through cadmium arachidate (C19H39COO)2Cd, monolayers have been determined from attenuation measurements of the core level photoemission (XPS) signals from gold, silver and indium substrates. Both fixed angle-variable overlayer thickness experiments and variable angle-fixed overlayer thickness experiments were performed. We derive a preferred value of 3.6 nm at 1117 eV and an E0.5 energy dependence over the narrow energy range considered. Values determined for bulk cadmium arachidate and arachidic acid from absolute intensity comparisons with gold and silver are close to the monolayer values. The results are discussed in the light of the controversy existing concerning other values of λ’s determined for organic and polymeric materials.