RESISTIVE MEASUREMENT OF THE TEMPERATURE-DEPENDENCE OF THE PENETRATION DEPTH OF NB IN NB ALOX/NB JOSEPHSON-JUNCTIONS/

The temperature dependence of the penetration depth of Nb films was de termined from resistive transitions of Nb/AlO(x)/Nb Josephson junction s in a constant magnetic field applied parallel to the junction planes . Distinct resistance peaks were observed as temperature decreases and those peaks were found to appear when the total flux threading the ju nction equals an integral multiple of the flux quantum. From this cond ition, the penetration depth at those peak positions has been determin ed. The temperature dependence was well described by either the dirty local limit or the two-fluid model. This method can be useful for a hi ghly fluctuating system such as high-temperature superconductors.