NE NEUTRAL ATOMS 180-DEGREES BACKSCATTERED FROM A PT(111) SURFACE IN THE 3-ATOM SCATTERING MODEL

The intensity of 180-degrees backscattered neutral atoms is investigated using numerical calculations based on the three-atom scattering model (THASM). The calculations are performed for 2 keV Ne+ ions incident along the [112BAR] direction of a Pt(111) surface. The THASM calculations well reproduce the maximum intensity in the polar-angle scan, which has been observed experimentally, and the peak position is strongly dependent on the interatomic potential. Also, the peak width (FWHM) is sensitive to thermal vibrations of surface atoms, especially to their anisotropies. The THASM results show that the Moliere approximation of the Thomas-Fermi potential with a reduced Firsov screening length, multiplied by a factor of 0.85, is suitable for the Ne-Pt interatomic potential, and that the vertical component of the surface Debye temperature is 143 K.