Influence of recoiling target atoms on kinetic electron emission from molybdenum under keV ion bombardments

Ion-induced kinetic electron emission from molybdenum in the energy range 0.7-40 keV is investigated using Monte Carlo calculations of the electron yield and the emission statistics, taking into account the electron excitation by ions and recoil atoms. The factor f0/ε evaluated by fitting the calculations to experimental electron yields decreases at low energy, and with heavy ions (f0: the escape probability through the surface, ε: the energy deposited to excite one electron). If the mass of the ion is larger than that of the target atom, the kinetic emission is dominated by the electron excitation by the recoils. With increasing mass of the ion, there is a complete antithesis between the emission statistics of the ion and of the recoils because of the energy transfer from the ion to the target atoms through frequent elastic collisions. (author)