Atomic hydrogen modification of copper surfaces studied by helium atom scattering

The structure and bonding of single crystal copper surfaces under irradiation by H atoms is investigated by helium atom scattering under UHV conditions. The effect of H atoms on CuCu bonding is deduced from the temperature dependence of the intensity of the specular He reflection from a clean Cu(110) surface and for irradiation with an effusive H atom beam. The Debye temperature deduced from the attenuation of the specular reflection decreases from 340 ± 10 K to 287 ± 10 K upon exposure to hydrogen atoms, implying a decrease in the surface Rayleigh phonon frequency by the HCu interaction. Also, the chemical reduction of a View the MathML source surface by irradiation with H atoms at 723 K is investigated. H atoms are shown to be an effective means for removing oxide impurities from Cu surfaces.