Effect of thermal vibrations and their correlations on grazing scattering of atoms from crystal surfaces

The influence of thermal vibrations of target atoms and their correlations on grazing scattering of keV atoms from crystal surfaces is investigated. Classical 2D and 3D trajectory calculations are performed and thermal vibrations are included using the Debye model as well as its high-temperature limit and uncorrelated thermal vibrations. Ion beam triangulation, rainbow structures for scattering along low-indexed directions of the surface plane, and polar angular distributions for impact along high-indexed directions are studied. We demonstrate that ion beam triangulation can be analyzed using uncorrelated thermal vibrations, while a realistic description of angular distributions requires more detailed modeling. For the peak positions of rainbow structures thermal vibrations play a minor role and they are well described by 2D simulations based on continuum potentials.