The surface diffusion of V and Cr atoms on tungsten

The dependence of activation energy Q and surface diffusion coefficient D on the concentration of adatoms θ has been investigated for Cr and V atoms migrating on tungsten. The changes of Q(θ) and D o(θ) could be explained by the lateral interaction of adatoms. The analysis of theoretical formulas obtained by D.A. Reed and G. Ehrlich for surface diffusion coefficient D is given. It is proposed to characterize the nonlinearity of the calculated curves of In D(θ, T) as a function of 1/ T by a correlation coefficient. An experimental dependence qualitatively fits the calculated curve. These results show that the sequence of the lateral interaction energy decrease is Cr, V, Ti. It is in agreement with the features of the electron structure of the atoms.