Laser Investigation of the Dynamics of Molecule-Surface Interactions

Abstract

In the past decade the interest in the dynamics of the interaction between molecules and clean and well-characterized solid-state surfaces has steadily increased [1]. Most information has been obtained from angular and velocity distribution measurements in surface scattering experiments, giving a complete insight into the dynamics only where atoms are involved. For molecules, however, it is necessary to have additional information on the internal state distribution. It was recently demonstrated that the population distribution of the rotational and/or vibrational states of the scattered molecules can be investigated by laser-induced fluorescence and laser-induced resonance ionization [2–12]. Furthermore, resonance ionization in connection with time-of-flight measurements gives information on the velocity distributions of the scattered particles [13]. As these measurements are angle and state-selective, they yield a full description of the average energy and momentum exchange between the molecules and the surface. Such investigations were performed in our laboratory for the NO/Pt system as well as for the weak inelastic NO/graphite system and are discussed in the following.