Coverage and structure of deuterium on Cu(111)

The absolute coverages of atomic deuterium adsorbed on the Cu(111) surface at a temperature of 100 K have been determined using nuclear reaction analysis (NRA), and correlated with thermal desorption spectra (TDS) and deuterium-induced low energy electron diffraction (LEED) patterns for Cu(111). It was found that the adsorption of deuterium saturates at a coverage of 0.67 +/- 0.03 ML, significantly lower than that observed for fcc(111) transition metal surfaces. The D coverage for a (2 x 2) LEED pattern was measured to be 0.5 ML, in common with those of H/Ni(111) and H(D)/Ag(111). No bulk absorption was observed, The low saturation coverage of D on Cu(111) is attributed to the combination of a low heat of adsorption and D-D repulsion on the surface.