| Autor: |
Shimakage, Hisashi, Tsujimoto, Kazuya, Wang, Zhen, Tonouchi, Masayoshi |
| Zdroj: |
Superconductor Science and Technology; December 2004, Vol. 17 Issue: 12 p1376-1380, 5p |
| Abstrakt: |
We fabricated MgB2/AlN/NbN trilayer Josephson junctions on c-plane sapphire substrates, and investigated the dependence of the MgB2 surface morphology on MgB2 growth temperature. AFM measurement showed that the grain size was about 150 nm and the surface roughness was about 10 nm when deposition was done at the highest critical temperature. The critical temperature of the MgB2 layer after SIS junction fabrication remained the same as that for bare MgB2 film. The currentvoltage characteristics of the MgB2/AlN/NbN junctions showed a very clear Josephson current and a gap structure. The critical current density was over 1 kA cm−2, and the ratio of the sub-gap resistance to the normal resistance was 16.6 when the AlN insulator thickness was 0.14 nm. The critical current was ideally modulated by applying a magnetic field, indicating that showed that the Josephson current flowed uniformly in the junctions. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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