EXPERIMENTAL TEST OF MODEL FOR ANGULAR AND ENERGY DEPENDENCE OF REFLECTION-ELECTRON-ENERGY-LOSS SPECTRA

摘要

Experimental inelastic electron-scattering cross sections of Si and Fe determined from reflection-electron-energy-loss spectroscopy (REELS) experiments are presented. Three primary energies of the electrons (300, 800, and 2000 eV) and three experimental geometries have been considered. The cross sections have been compared with those determined according to a theoretical model introduced in the preceding paper [F. Yubero et at, Phys. Rev. B 53, 9719 (1996)]. The agreement between theory and experiment is good, considering that the theoretical cross sections are calculated from first principles, without adjustable parameters. For a fixed primary electron energy the inelastic mean free path, for both Si and Fe, is found to decrease for more glancing trajectories. The characteristic length for the path-length distribution function of the REELS electrons is found to be smaller for Fe than for Si and to decrease with energy for both materials. [References: 25]