Length scale effects on the electronic transport properties of nanometric Cu/Nb multilayers

In this paper, we investigated the contributions of the interface and grain boundary scattering to the resistivity of Cu/Nb multilayers with several bilayers thickness. We carried out temperature-dependent resistivity, transmission electron microscopy (TEM), and X-ray absorption fine structure (XAFS) measurements. We investigated possible structural changes inside the Cu layer by using XAFS measurements which indicated that the local structure around Cu sites remains face centered cubic even for the shortest bilayer period. Also, we obtained the grain size values by using TEM measurements so that we could evaluate the grain boundary contribution to the resistivity. The resistivity seems to be related to the thickness of the individual layers rather than the total film thickness. Our results agree well with theoretical calculations and we were able to obtain the relative importance of the grain boundary and the interface scattering. We found a clear correlation between fine structure length scales (grain size and layer thickness) and macroscopic properties (resistivity). Published by Elsevier B.V.