Sputter-deposited thin films of Cu3Ba2YO7 on Al2O3 substrates were studied by using 3.2MeV 4He+ Rutherford back-scattering spectrometry. The effects of morphological changes in the films during annealing were factored out by exploiting data on thickness distributions which had been obtained by means of atomic force microscopy. The resultant diffusivity values were more than 20 times smaller than those which had previously been reported.

Y.Igarashi, Y.Fujino, N.Suzuki, K.Iimura: Journal of Applied Physics, 1994, 76[10], 5724-30