The diffusion of Xe on Nb(110), from 48 to 70K, was studied by using linear optical diffraction from laser-induced Xe density gratings. The diffusivity could be described by the Arrhenius relationship,

D (cm2/s) = 1.7 x 10-6 exp[-0.054(eV)/kT]

Density-functional theory calculations were also made of the binding energy for Xe on Nb(110). The preliminary results showed that Xe preferred on-top sites, with a binding energy of 0.247eV, and moved by hopping over short-bridge sites, with an activation energy barrier of 0.051eV; in close agreement with the experimental value.

P.Thomas, J.Gray, X.D.Zhu, C.Y.Fong: Chemical Physics Letters, 2003, 381[3-4], 376-80