The He/Pd (110) interaction potential

Four bound-state resonances have been observed using He scattering from a Pd (110) surface. The bound-state energies can be fitted with good accuracy to a Morse potential with depth D=-8.05 meV and range parameter sigma =0.85 AA -1. The shape of the potential shows that the repulsive part is appreciably 'softer' for metals than for alkali halides and graphite. The effective corrugation amplitude perpendicular to the close-packed metal rows z(01)=0.22-0.24 AA is similar to Ag (110) and appreciably larger than for Ni (110) and Cu (110).