A new technique, which involved a pulsed supersonic molecular beam source and time-resolved surface infra-red spectroscopy, was used to measure the microscopic diffusion of molecules on surfaces. After rapidly dosing a periodically stepped (111) crystal face to a total coverage of 0.006 of a monolayer of CO, temporal changes in the migration of CO molecules from terrace to step sites were monitored with a resolution of up to 0.005s. When compared with a simple kinetic model, the data revealed the statistical microscopic hopping rates, for CO diffusion on the (111) plane, at temperatures of between 95 and 195K.

J.E.Reutt-Robey, D.J.Doren, Y.J.Chabal, S.B.Christman: Physical Review Letters, 1988, 61[24], 2778-80