Electrical conduction in Cu/Cr multilayer films at low temperatures

The bilayer wavelength dependence of the electrical resistivity and the temperature coefficient of the resistance (TCR) of Cu/Cr multilayer films deposited by successive electron beam evaporation of Cu and chromium is reported. Copper exhibits very low resistivity (1.7x10 exp -8 Omega m) and Cr high resistivity (13x10 exp -8 Omega m) and the two metals have different structures and are immiscible. Both the electrical resistivity and TCR of Cu/Cr multilayers show oscillatory behaviour as a function of bilayer wavelength. The transition from metallic to non-metallic behaviour observed may be due either to structural changes or to changes in the electronic structure. The resistivity at room temperature is approximately proportional to the inverse of the bilayer wavelength.