THE INTERACTION OF HYDROGEN WITH THE (110) SURFACE OF NIAL

The adsorption of hydrogen onto the (110) surface of the ordered alloy NiAl is being investigated experimentally and theoretically. At this stage, the experimental and theoretical results are complementary. Exp eriment reveals that the dissociative adsorption of atomic hydrogen is activated and indicates that the presence of H on the surface causes dramatic changes in the atomic positions of the Ni and Al atoms. Densi ty functional theory for a (1 x 1) H overlayer identifies the H bondin g site as the Ni-Ni bridge and predicts the surface rippling on clean NiAl(110) is removed by hydrogen.