Interface microstructure of MgB2/Al-A1Ox/MgB 2 Josephson junctions studied by cross-sectional transmission electron microscopy

Kenji Ueda, Shiro Saito, Kouichi Semba, Toshiki Makimoto, Michio Naito

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We investigated the interface microstructure of sandwich-type MgB 2/Al-AlOx/MgB2 Josephson tunnel junctions by cross-sectional transmission electron microscopy (TEM) in order to clarify the non-idealities in the junction characteristics. The results indicate that there are poor-crystalline MgB2 layers and/or amorphous Mg-B composite layers of a few nanometers between the AlOx barrier and upper MgB2 layer. The poor-crystalline upper Mg-B layers seem to behave as normal metal or deteriorated superconducting layers, which may be the principal reason for all non-idealities of our MgB2/Al-A1Ox-/ MgB2 junctions.

Original languageEnglish
JournalJapanese Journal of Applied Physics, Part 2: Letters
Issue number12-16
Publication statusPublished - 2007 Apr 13
Externally publishedYes



  • Film
  • Josephson junctions
  • MBE
  • MgB
  • TEM

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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