NMR STUDY OF HYDROGEN ADSORBED ON COPPER-NICKEL ALLOYS.

The adsorption states of hdyrogen on Cu//1//0//0// minus //xNi//x(x equals 0-10) alloys were studied by nuclear magnetic resonance NMR, and the proton resonance shift was found to decrease and the line width to increase with increasing Ni concentration x. Steep changes in the shift and the line width were observed in the range of low Ni concentration (x less than 1). The decrease in the shift is attributable to the rapid exchange of H adatoms between sites in the Cu environment and sites of Ni or Cu atoms in contact with the Ni atoms. Since H adatoms on the latter sites are spin-polarized by Ni 3d-electrons via conduction s-electrons, their shifts are smaller than those for H adatoms on the former sites.