Using a linear optical diffraction technique, a systematic investigation was made of defect effects on the quantum surface diffusion of H on Pt(111) surfaces. The quantum tunneling effect was clearly observed for H diffusion at low temperatures as manifested by a leveling off of the diffusion coefficient on flat surfaces. The strong influence of surface defects on the quantum diffusion was in good agreement with the creation of an inhomogeneous surface with adsorption sites of different binding energies.

Quantum Diffusion of H on Pt(111) - Step Effects. C.Z.Zheng, C.K.Yeung, M.M.T.Loy, X.Xiao: Physical Review Letters, 2006, 97[16], 166101 (4pp)