AVS 46th International Symposium
    Surface Science Division Wednesday Sessions
       Session SS2-WeA

Paper SS2-WeA4
Quantum-State-resolved Studies of Elastic and Inelastic Scattering of H@sub 2@ from Cu and Pd

Wednesday, October 27, 1999, 3:00 pm, Room 607

Session: Gas-Surface Dynamics
Presenter: G.O. Sitz, The University of Texas, Austin
Authors: G.O. Sitz, The University of Texas, Austin
E. Watts, The University of Texas, Austin
Correspondent: Click to Email
The scattering of H2 from Cu and Pd surfaces was studied using molecular beam techniques and quantum state-specific detection methods. A comparison is made for an unreactive case, H2(v=0)/Cu, and two reactive cases, H2(v=1)/Cu and H2(v=0)/Pd. Rotational excitation was observed in the scattering of H2(v=0) from Pd(111) and Cu(110) and was found to depend on the surface temperature. This rotational excitation occurred even when there was insufficient translational energy to account for the gain in rotational energy, indicating that part of the excitation energy is transferred from the surface to the molecule. The effect of vibrational motion in the H2/Cu system was studied by preparing the incident molecules in the single rovibrational state (v=1, J=1). The absolute survival probability of this state was measured along with the probabilities for rotational excitation and vibrational relaxation. This information is used to estimate the probability of dissociation of the vibrationally excited state. These results are compared with recent quantum dynamical calculations for the scattering of this particular state.