COMPUTER STUDIES OF SURFACE-STRUCTURE OF NIAL(111)

The 180-degrees neutral impact-collision ion scattering spectroscopy (NICISS) data have been analyzed using the ACOCT program code based on the binary collision approximation (BCA) The computer simulations are performed for the case of 2 keV He+ ions incident along the [121BAR] direction of a NiAl(111) surface. It is found that the experimental results are well reproduced by the ACOCT simulations including the inward relaxation of 40% of the first interlayer spacing on Ni terminated layer at the NiAl(111) surface and including the Moliere approximation of the Thomas-Fermi potential with a reduced Firsov screening length, multiplied by a factor of 0.60.