Electronic transport properties of double layer metallic films

Size effect modifications of the normal and Hall resistivities for copper and copper-ferromagnetic amorphous double layer metallic films are studied vs. the thickness of copper deposited on the top of the amorphous substrate. Experimental data are compared with calculations derived from the Fuchs-Sondheimer theory, as developed by Bergmann. For copper, one can see that the size effect on the resistivity tends to approach the theoretical behaviour when the deposition of the copper film on the substrate is uniform, as on an amorphous metallic film. The calculation of the Hall resistivities for the double layer samples reproduces quite well the experimental values obtained in correspondence to a magnetic field higher than the saturation induction of the samples. These results suggest that the theory could achieve better results than those found by Bergmann if certain simplifications are avoided.