High quality MgB2/insulator/Pb Josephson tunnel junctions with two different barriers were studied. The junctions were fabricated using MgB3 films grown by hybrid physical-chemical vapor deposition and the barriers were formed at different temperature regions. Both kinds of junctions show clear tunneling characteristics with clear Josephson supercurrent, high IcRN products, and the expected Ic(B) pattern. The junctions with barriers formed at 200 to 450°C have higher I cRN, larger MgB2 π gap values, thinner barriers and higher barrier heights than the junctions with barriers formed over 700°C. In addition, some intermediate temperature barrier junctions show features due to the ógap of MgB2, which were not observed in the high temperature barrier junctions. High device yield Indicates that the approaches to form tunnel barriers are promising for device fabrications.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering