The research lead to better understanding of segregation kinetics and mechanism of surface active elements such us Sb, Sn and Se on the surface of polycrystalline alloy FeSiAl as well as on grain boundaries. The new experimental method based on Auger Electron Spectroscopy was developed for "in situ" studies of surface segregation Sb, Sn in ultrahigh vacuum (UHV) at elevated temperatures. We have established the surface segregation dependence of crystallographic orientation of surface grains. We have estimated segregated thin film thickness on grains with different crystallographic orientation to less than one monolayer. We have developed new experimental technique to study oxide layers of sintered soft magnetic nanocrystalline composite powders for use in high frequency range. The study of hydrogen outgassing of thin stainless steel to UHV, showed that the diffusion model of hydrogen outgassing used for several decades is not appropriate for outgassing process modelling, because the recombination of hydrogen atoms on the surface hindered the dynamics of the process. The good agreement of our experimental results and recombination model was established