ANGLE-RESOLVED VELOCITY DISTRIBUTIONS OF EXCITED RH ATOMS EJECTED FROM ION-BOMBARDED RH(100)

The distributions of metastable excited state (F-4(7/2)) and ground state (F-4(9/2)) Rh atoms ejected from Ar+-bombarded Rh{100} are experimentally determined as a function of ejection velocity and angle. Corresponding theoretical predictions are made by incorporating a nonradiative deexcitation model into molecular dynamics simulations of the bombardment process. There is good agreement between the experimental and theoretical distributions. Th simulations show that a fraction of the ejected atoms are excited via collisions 1-20 angstrom above the surface, and that these atoms make a significant contribution to the excited atom yield low ejection velocities.