Fabrication of layered metallic systems for perpendicular resistance measurements

We are studying the resistivity of layered metal systems in a direction perpendicular to the layers (ρperp). The techniques for measuring the very small resistances involved are briefly reviewed, and the system for producing samples with the appropriate geometry is discussed in detail. The samples are produced by sputtering in an ultrahigh vacuum compatible system that permits mask changing without breaking the vacuum. As an example, we give results illustrating the Cooper pair-breaking effects of thin layers of Co in a system consisting of consecutive layers of Nb–Co–Ag–Co–Nb.