Title :
Tunnel junctions on as-grown superconducting MgB2 thin films
Author :
Ueda, K. ; Naito, M.
Author_Institution :
NTT Basic Res. Labs., NTT Corp., Kanagawa, Japan
fDate :
6/1/2003 12:00:00 AM
Abstract :
We demonstrate that good superconductor/insulator/normal-metal tunnel junctions can be fabricated on as-grown superconducting MgB2 thin films. The as-grown films were prepared by coevaporation at low growth temperatures of around 280°C. The insulating barrier was formed by an Mg overlayer, which is subsequently oxidized in air. The tunneling spectra for Au/MgOx/MgB2 junctions showed a reproducible and well-defined superconducting gap (Δ=∼2.5 meV). The resultant 2Δ/kBTc was significantly smaller than the predicted BCS value of 3.52.
Keywords :
BCS theory; Josephson effect; gold; magnesium compounds; superconducting energy gap; superconducting thin films; superconductive tunnelling; type II superconductors; 2.5 meV; Au-MgOx-MgB2; Au/MgOx/MgB2 junctions; as-grown superconducting MgB2 thin films; coevaporation; predicted BCS value; superconducting gap; superconductor/insulator/normal-metal tunnel junctions; tunnel junctions; tunneling spectra; Fabrication; Gold; High temperature superconductors; Insulation; Josephson junctions; Spectroscopy; Superconducting films; Superconducting thin films; Superconductivity; Tunneling;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.812213
