The inelastic mean free path and the inelastic scattering cross-section of electrons in GaAs determined from highly resolved electron energy spectra

GaAs samples have been studied with a hemispherical analyser of high resolution (type ESA 31). The analyser covers the energy range 10-5000 eV with controlled energy resolution. Prior to measurements, sample surfaces have been exposed to Ar+ ions in order to amorphise the surface layer. This procedure resulted in Ga enrichment (70-85 at.% Ga as determined by XPS). The elastic peak and EELS spectra were measured in the loss range E-E-1 of 50 eV. The elastic peak intensity ratios of GaAs sample and the Ni reference were used to determine the IMFP in GaAs. The relations between these ratios and the IMFP have been determined from Monte Carlo simulation of the elastic backscattering effect. The values of the IMFP resulting from this procedure are in reasonable agreement with the literature data. The inelastic scattering cross-sections have been determined using the Tougaard procedure. The energy loss distributions lambda(i)K are presented in the 0.2-5.0 keV range. (C) 1998 Elsevier Science B.V. All rights reserved.