Zusammenfassung
The dynamics of Xe trapping on Pt(111) was studied using supersonic
atomic beam techniques. Initial trapping probabilities (S0) were
measured directly as a function of incident translational energy
(EinT) and angle of incidence (thetai) at a surface temperature
(Tins) 95 K. The initial trapping probability decreases smoothly
with increasing ET costhetai;, rather than ET cos2thetai, suggesting
participation of parallel momentum in the trapping process. Accordingly,
the measured initial trapping probability falls off more slowly with
increasing incident translational energy than predicted by one-dimensional
theories. This finding is in near agreement with previous mean translational
energy measurements for Xe desorbing near the Pt(111) surface normal,
assuming detailed balance applies. Three-dimensional stochastic classical
trajectory calculations presented herein also exhibit the importance
of tangential momentum in trapping and satisfactorily reproduce the
experimental initial trapping probabilities.
Nutzer