We have fabricated MgB2/Insulator/Pb Josephson tunnel junctions on MgB2 films deposited by hybrid physical-chemical vapor deposition using native oxide as the tunnel barrier. For the critical current of the junction on MgB2 (0001) film, its temperature dependence follows the Am- begaokar-Baratoff relation and its magnetic field dependence exhibits a Fraunhofer pattern. From analysing the magnetic field dependence of the critical current of the junction on c-axis tilted MgB2 film, we find small contribution of the Josephson current from the ab-plane tunneling, which may suggest a π phase difference between the order parameters of MgB 2π and δ bands.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering