High field critical current densities for a thick Nb12Al3Ge superconductor made by high-rate sputtering

High current densities were measured for a 66-μm-thick sputter-deposited Nb12Al3Ge superconductor in magnetic fields from 100 to 210 kOe. Critical currents at 4.2°K were 2.5×105 A/cm2 at 100 kOe, 1.3×105 A/cm2 at 150 kOe, 2.6×104 A/cm2 at 200 kOe, and 1.5×104 A/cm2 at 210 kOe. The current densities were comparable to current densities reported for Nb3Sn and V3Ga. The deposit was made at a rate of 1 μm/min and heat treated 20 days at 750°C prior to the current density measurements.