EXPERIMENTAL-DETERMINATION OF THE INELASTIC MEAN FREE-PATH FOR CU, AG, W, AU AND TA, IN THE ENERGY-RANGE 500-3000 EV BY ELASTIC PEAK ELECTRON-SPECTROSCOPY AND USING NI REFERENCE SAMPLE

The inelastic mean free path (IMFP) is the most important electron tra nsport parameter. The value of IMFP can be determined by electron refl ection experiments (EPES) supported by the Monte Carlo theory with the multiple elastic scattering events considered. The values of IMFP for the high atomic number elements obtained from such a model and applyi ng Al standard were found to be in reasonable agreement with the theor etical values. Recently Ni has been proved to be a more adequate refer ence sample due to the lack of inelastic losses appearing in the vicin ity of the elastic peak. In the present work the energy dependence of the IMFP for Cu, Ag, W, Ta and Au using Ni standard was evaluated by E PES in the energy range 500-3000 eV. The Ni standard of high qualify w as used, where its surface roughness was verified by scanning tunnelli ng microscopy. Reasonable agreement with Tanuma at al. results was obt ained in the energy range 500-2000 eV. Above 2000 eV the obtained resu lts were in agreement with the values by Ashley and Tung.