Sticking, Adsorption, and Absorption of Atomic Hydrogen on Cu(110)

The sticking coefficient of atomic hydrogen at T sub G = 1815K on a Cu(110) surface has been determined to be 18%. In addition to the buildup of a chemisorption layer, the absorption of atomic H into subsurface sites is observed. The subsurface sites are thermally less stable than the chemisorption sites. Model calculations for the phononic energy transfer and estimates for the parallel momentum transfer and for electron-hole pair excitation indicate that the first two mechanisms dominate the accommodation process.