Surface diffusion of Xe on Nb(1 1 0)

We studied Xe diffusion on Nb(1 1 0) from 48 to 70 K using the linear optical diffraction from laser-induced Xe density gratings. The diffusion rate is characterized by an Arrhenius behavior with an activation energy of Ediff=54 meV and a diffusivity D0=1.7×10−6 cm2/s. We also performed a density-functional theory calculation of the binding energy for Xe on Nb(1 1 0). Our preliminary result shows that Xe prefer on-top sites with a binding energy of 247 meV, and move by hopping over short-bridge sites with an activation energy barrier of 51 meV, in close agreement with the experimental value.