Indium-Impregnated Porous Glass: Magnetotransport and Superconducting Transition

Abstract

ABSTRACTMeasurements of the resistive superconducting transition and magnetoresistance of indium metal in the restricted geometry of 50 Å size porous Vycor glass are reported. We have mapped out the upper critical magnetic field versus temperature phase diagram for these transitions for fields up to 20 T and temperatures down to 100 mK. The results are consistent with magnetization measurements by previous authors and can be generally interpreted in terms of the description of inhomogeneous type-II superconductors. The field-induced resistive transitions exhibit unusual behavior not probed by previous bulk-type measurements which may be related to the microstructure of the composite.