The dynamics of krypton trapping on Pt(1 1 1) at 50 K: experiment and molecular dynamics simulation

The dynamics of krypton trapping on clean Pt(1 1 1) were investigated using supersonic molecular beam techniques at a surface temperature of 50 K. The initial trapping probability of Kr scales with normal incident energy (ET cos2θ), indicating a smooth gas–surface potential. The Kr trapping probability decreases from 0.8 to 0 as the incident normal energy is increased from 2 to 23 kJ/mol. Trapping on the krypton-saturated monolayer is greatly enhanced at all incident energies and angles compared to the clean surface, and exhibits near total energy scaling (ET cos0.3θ), indicating a corrugated gas–surface potential. Stochastic trajectory simulations [J. Chem. Phys. 105 (1996) 1609] using a Morse potential with parameters based on simulations of Ar trapping [J. Chem. Phys. 94 (1991) 1516] agree with the experimentally measured energy and angular dependence of the trapping probability of Kr.