عنوان مقاله [English]
The electronic properties of thin films and nanostructures as well as the surface electronic structure can be obtained using Reflection electron energy loss technique at low energy. In this work, dielectric function of SrTiO3 is obtained by Yubero-Tougaard method using the experimental inelastic cross section obtained by Tougaard-Chorkrndorf method. Theoretical cross section obtained at energy 1423 eV, incidence angle 15 and exit angle 35 was found to be in good consistence with experimental cross section. In addition, the angular distribution of surface excitation parameter for this crystal was determined at energies 1000, 1423, 2000, 2500 and 3000 eV. To this end, the definition presented by Pauly and Tougaard was used which relies on the variation in excitation probability at surface and moving in semi-infinite medium. This parameter was calculated based on the differential inelastic electron dispersion cross section using QUEELS software which is valid for reflection electron energy loss spectrum.