Subsurface states diagnostics of crystals by low-energy electrons

The fine structure (FS) of the experimental secondary electron emission spectra (SEES) along the normal to Ir(111), Pt(111) surfaces and the target current spectra (TCS) of Au(111), Cu(111) surfaces are interpreted theoretically. The energy dependence of the band level broadening, the electron-electron and electron-plasmon contributions to the nonequilibrium electron distribution function, the isotropic component of current from the electrons scattered on the surface were taken into account for calculation. It is shown that the PS of SEES and TCS is mainly due to the electronic structure of finite states to which the electrons come or from which they emit. The predominant role of the effects of bulk energy-band structure in the formation of spectra is shown. The developed method enables on the distinguish between the bulk effects in the spectra and the surface ones