A Monte Carlo simulation method has been used to calculate the reflection electron energy loss spectrum for Ag. The differential inelastic cross-section is obtained from an inhomogeneous electron self-energy in the surface region. A comparison of the calculation result with an experiment shows a remarkable agreement on the spectrum shape. The simulation has clearly shown the component to the surface plasmon excitation due to individual scattering processes along trajectory part, i.e., the loss in vacuum before reflection, the loss in vacuum after reflection and loss in metal events. It is found that the bulk plasmon feature is overwhelmed by the intense surface plasmon feature in the measured spectrum peak at about 3.7 eV. However, 7.5 eV peak contains both surface- and bulk-excitation character.

The study of inelastic scattering of electrons moving in a surface region is important to a comprehensive understanding of the basic process of electron-surface interaction in a surface electron spectroscopy. A numerical formalism was previously developed to calculate the complex electron self-energy near a metal surface. This inhomogeneous self-energy in the depth about the surface is formulated in terms of a wave-vector-dependent dielectric function which is obtained from the optical data. In this paper, we present a numerical calculation result on the spatially varying differential inelastic scattering cross section and the inelastic mean free path. Combining this inelastic scattering cross section and the Mott cross section for electron elastic scattering has led to a Monte Carlo simulation model for electron interaction with a surface. To verify this simulation model we have carried out simulations of reflection-electron-energy-loss spectroscopy (REELS) spectra for Au and Si, and compared the results with the experimental spectra. The comparison of the spectra shape for Au is quite reasonable. Several surface features for Au having lower-energy losses have been clearly identified, while the higher-energy loss peaks are shown to be mainly of the bulk feature. The simulation result indicates that the energy-loss process of electron in the vacuum region after leaving from a surface makes a dominant contribution to the surface excitation peaks observed in a REELS spectrum.

We present a fitting calculation of energy-loss function for 26 bulk materials, including 18 pure elements (Ag, Al, Au, C, Co, Cs, Cu, Er, Fe, Ge, Mg, Mo, Nb, Ni, Pd, Pt, Si, Te) and 8 compounds (AgCl, Al₂O₃, AlAs, CdS, SiO₂, ZnS, ZnSe, ZnTe) for application to surface electron spectroscopy analysis. The experimental energy-loss function, which is derived from measured optical data, is fitted into a finite sum of formula based on the Drude-Lindhard dielectric model. By checking the oscillator strength-sum and perfect-screening-sum rules, we have validated the high accuracy of the fitting results. Furthermore, based on the fitted parameters, the simulated reflection electron energy-loss spectroscopy (REELS) spectrum shows a good agreement with experiment. The calculated fitting parameters of energy loss function are stored in an open and online database at http://micro.ustc.edu.cn/ELF/ELF.html.

Monte Carlo simulation methods for the study of electron beam interaction with solids have been mostly concerned with specimens of simple geometry. In this article, we propose a simulation algorithm for treating arbitrary complex structures in a real sample. The method is based on a finite element triangular mesh modeling of sample geometry and a space subdivision for accelerating simulation. Simulation of secondary electron image in scanning electron microscopy has been performed for gold particles on a carbon substrate. Comparison of the simulation result with an experiment image confirms that this method is effective to model complex morphology of a real sample. SCANNING 34: 145–150, 2012.

The primary energy dependecne and atomic-number dependence of backscattered electrons in Auger electron spectroscopy in the $EN\left(E\right)$ mode have been investigated both theoretically and experimentally. A Monte Carlo simulation method with inclusion of cascade-secondary-electron production has been used to calculate the full energy distribution of backscattered electrons from the elastic peak down to the true-secondary-electron peak. The simulation model is based on the use of a dielectric function for describing inelastic scattering and secondary excitation, and on the use of Mott cross sections for elastic scattering. A systematic comparison between the calculated and experimental spectra measured with a cylindrical mirror analyzer has been made for $\mathrm{Au}$ , $\mathrm{Ag}$ , and $\mathrm{Cu}$ and for primary energies ranging from 0.5 to $5\mathrm{keV}$ . Reasonable agreement was obtained for the backscattering background at primary energies in the $\mathrm{keV}$ region. A significant contribution of cascade-secondary electrons to the measured spectra on the low-energy side (less than $200\mathrm{eV}$ ) was found. Experiments performed on elements with a wide range of atomic numbers have shown a quantitative common curve of the backscattering continuum when plotted on a logarithmic intensity scale in the intermediate energy region between $200\mathrm{eV}$ and the low-loss peaks.