Surface Temperature Dependence of Rotational Excitation of H2 Scattered from Pd(111)

BUSNENGO, H.F.; DONG, W.; SAUTET, PH.; SALIN, A.

PHYSICAL REVIEW LETTERS

Año: 2001 vol. 87 p. 127601 - 127604

0031-9007

Classical dynamics simulations are performed to study rotational excitation of H2 scattered from Pd(111), taking into account energy exchange with surface phonons through a 3D surface oscillatormodel. We show that dynamic trapping, identified recently in the study of dissociation dynamics, plays a prominent role. The corresponding long interaction time due to several recollisions allows an efficient energy exchange between H2 molecules and surface phonons. This microscopic mechanism explains the puzzling experimental finding on the role of surface temperature in H2(v=0, J=1->3 excitation.