S.I.S. devices are typically made using Niobium (Nb),a refractory metal that exhibits superconductor behavior at around nine degrees Kelvin.
Our S.I.S. devices were fabricated at AMC and tested in our R.A. lab, either by Liquid Helium dipping or with a CTI cryostat mounted multiple four point probe apparatus originally designed by Dr. Graham Walker. Test results of two good devices with transitions to the super conducting region at 12 and 13.5 degrees Kelvin are available here. The test was done with the apparatus mounted on the second stage of our CTI 1 watt cryostat.