National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan1
Department of Electrical Engineering, Kangwon National University, Kangwon 25913, Republic of Korea2
School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, QLD 4072, Australia3
Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, 4072 Australia4
School of Chemical Engineering, Faculty of Engineering, Architecture and Information Technology (EAIT), The University of Queensland, Brisbane, Queensland 4072, Australia5
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, New South Wales 2500, Australia6
A superconducting joint of unreacted monofilament internal magnesium diffusion (IMD) processed magnesium diboride (MgB2) wires was fabricated by exploiting the diffusion phenomenon of magnesium into the boron layer inside the superconducting joint. Unprecedentedly, the joint was able to carry almost identical transport current compared to the bare wire in 2 T to 7 T magnetic field at 20 K. The joint also exhibited very low joint resistance of 2.01 × 10-13 W in self-field at 20 K. Among commercially available all the superconductors, this work is the first to successfully realize a superconducting joint, which is capable of transferring current from one conductor to another without any notable degradation under strong magnetic fields. This work demonstrates great potential to apply IMD processed MgB2 conductors in a range of practical applications, where superconducting joints are essential.
Keywords: Magnesium Diboride (MgB2), Internal Magnesium Diffusion (IMD), Superconducting Joints