A nuclear magnetic resonance study was made of interdiffusion at the interfaces between epitaxially grown laminae of rare-earth metals. The present system consisted of a superlattice which had been grown by means of molecular beam epitaxy at about 270C. The nuclear magnetic resonance spectrum of 159Tb exhibited satellites that were associated with Tb ions having various numbers of Y neighbors, and this provided information concerning the Y concentration profiles that resulted from interdiffusion. The results were explained in terms of a model that was based upon thermally activated diffusion and which allowed for a progressive decrease in the root-mean-square diffusion length from the lowest to the highest interface. The diffusion coefficient, which was assumed to be independent of the composition, was found to be equal to 9.0 x 10-13m2/s at the growth temperature.

Y.Li, J.W.Ross, M.A.H.McCausland, D.S.P.Bunbury, R.C.C.Ward, M.R.Wells: Journal of Physics - Condensed Matter, 1997, 9[29], 6301-11