THE SURFACE-DIFFUSION OF V-ATOMS AND CR-ATOMS ON TUNGSTEN

The dependence of activation energy Q and surface diffusion coefficien t D on the concentration of adatoms theta has been investigated for Cr and V atoms migrating on tungsten. The changes of Q(theta) and D0(the ta) could be explained by the lateral interaction of adatoms. The anal ysis of theoretical formulas obtained by D.A. Reed and G. Ehrlich for surface diffusion coefficient D is given. It is proposed to characteri ze the nonlinearity of the calculated curves of ln D(theta, T) as a fu nction 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 i s in agreement with the features of the electron structure of the atom s.