Low energy ion scattering as a tool of investigation of defect surfaces

Full text: The peculiarities of the low energy Ne+ and Ar+ ion scattering from the defect GaP(100) and ice surfaces at grazing incidence were investigated by computer simulation. In our calculations we used model of binary collision approximation. The universal Ziegler-Biersack-Littmark potential was chosen as a potential of interaction. The trajectory of ions scattered from defect structure was studied. Analyzing the trajectory of ion scattering at defects located near the surface has been captured to semichannels. By influence of defects which located on the second and therein under layers, ions are channeled and after dechanneling reflected from crystal. The energy distributions of the particles reflected from the defect GaP(100) and ice surfaces have been calculated. In the case when the surface is a stepped, at grazing angles of incidence by the position of the single scattering peak in the energy spectrum of particles scatted to 90 one can identify a type of step atoms formed on the surface of single crystal. The computational results show that in the energy spectrum the characteristic peaks corresponding to scattering of ions by the surface atomic chains and semichannels are observed. The situation and intensity of these peaks depend on the geometrical shape of the surface semichannels. The computer simulation allowed an investigation of the effect of the atomic steps on the single crystal surfaces upon the trajectory features of the ions being scattered along the ridge of the atomic chains and undergoing the surface hyper channeling and semichanneling. (authors)