Dilute Al-Mn Alloys for Superconductor Tunneling and Other Devices

Abstract

The authors present tunneling results for junctions comprising Mn doped Al films produced by sputter deposition, with Mn concentrations in the range of 0-5000 ppm. Our results for S I S , S I S, and N/I/S junctions demonstrate that Al-Mn alloys can serve both as superconductors with critical temperatures reduced from that of Al and as normal metals. The authors find Al-Mn in this doping range to be otherwise identical to pure Al in terms of its BCS-like tunnel characteristics (for superconductors) and its ability to produce high-quality tunnel barriers.

Realization of Precise Tuning the Superconducting Properties of Mn-Doped Al Films for Transition Edge Sensors

“…Magnetically doped superconducting films are excellent candidates to make TESs and Mn-doped aluminum is a representative material of this kind. Currently, magnetron-sputtering methods are mainly used to grow AlMn films [10,28,29]. Because it is difficult to precisely control the Mn concentration in the sputtering target and inconvenient to frequently replace the target, tuning the Tc of AlMn films relies on post-deposition annealing [24].…”