INTERACTION OF SLOW-ELECTRONS WITH LANGMUIR-BLODGETT-FILMS STUDIED BYHIGH-RESOLUTION ELECTRON-ENERGY-LOSS SPECTROSCOPY

Vibrational and complete high resolution spectra (HREELS) of Langmuir- Blodgett (LB) monolayers of mixtures of pure hydrogenated and deuterat ed stearic acids on aluminum substrates were recorded. The results sho w that electrons penetrate into the film and relax in the conduction b and of the insulating film. Complete spectra are mainly composed of di fferent regions corresponding to vibrational losses, and to exponentia l decay of the intensity of backscattered electrons where superimposed structures, fixed to the vacuum level, are observed for primary energ ies higher than 4 eV. An emission of thermalized electrons is also obs erved near the vacuum level. Conclusions about the different aspects o f this interaction are inferred combining information obtained from th e different regions in the spectra.