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The spatial distributions of ions (K+, Na+) passed through thin polycrystalline and single-crystalline Al films with the thickness from 180 to 600 Angstrem and critical channeling angles have been studied. The ion energies have been varied within the range E0=10-30 keV. It has been shown that an increase in the energy of the primary ion beam leads to a decrease in the width of the maxima of the angular distribution, which is associated with a decrease in the critical channeling angle psicr. It has been found that the value psicr does not exceed 4-50 for axial channeling and 9-100 for planar channeling Keywords: critical angle, passage of ions, angular distribution, channeling, spatial distribution.

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The effect of the adsorption of Ba atoms with a thickness of theta≤3-4 monolayers and the implantation of Ba+ ions with an energy of E0=0.5-2 keV on the density of states of electrons in the valence band, the parameters of the energy bands, and the emission and optical properties of Ge(111) has been studied for the first time. It is shown that during the adsorption of Ba atoms with theta=1 monolayer, the value of the thermoelectric work function φ decreases by ~ 1.9 eV, and the value of the secondary electron emission coefficient and the quantum yield of photoelectrons Y increases by 1.5-2 times. In the case of implantation of Ba+ ions with E0=0.5 keV at an irradiation dose D=6·1016 cm-2, the density of state of valence electrons and the parameters of the energy bands change sharply; the quantum yield of photoelectrons increases by a factor of 2 or more. The observed changes are explained by the formation on the surface of a thin (~25-30 Angstrem) amorphous doped layer consisting of nanoscale phases of the Ba-Ge type (~60-65 at.%). And excess (unbound) Ba and Ge atoms. In this case, the band gap Eg decreases by ~ 0.3 eV. Keywords: Ion implantation, quantum yield of photoelectrons, emission efficiency, heating, band gap, amorphous layer.