Energy loss function for Si determined from reflection electron energy loss spectra with factor analysis method

The Si energy loss function (ELF) for energy loss Delta E less than 30 eV was obtained from experimental lambda(E) K(Delta E) distributions using a factor analysis method lambda(E) K(Delta E), which are the products of the in elastic mean free path (IMFP) [lambda(E)] and the differential inverse IMFPs or inelastic scattering cross sections [K(Delta E)], were obtained from angle-resolved REELS at various primary beam energies with QUASES-XS-REELS software. The application of the factor analysis method to determine the ELF is described in detail. We performed factor analysis on the data matrix formed by lambda(E) K(Delta E) spectra to separate surface-and bulk-loss components. Finally, the ELF for Si was derived from extracted bulk-loss component by an iterative calculation. The resulting ELF is in good agreement with the ELF from Palik's optical data. The suggested approach should be applicable as a general method to determine ELF from REELS. Copyright (C) 2010 John Wiley & Sons, Ltd.