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      https://www.ias.ac.in/article/fulltext/boms/014/04/1119-1123

    • Keywords

       

      High temperature superconductors; Josephson effect; microbridge; Bi-Sr-Ca-Cu-O films; spray pyrolysis

    • Abstract

       

      Superconducting Bi-Sr-Ca-Cu-O (2212) films were prepared by spraying stoichiometric aqueous solutions of nitrates of bismuth, strontium, calcium and copper on heated MgO (100) substrates and subsequent annealing in air. TheR-T curves of the films show metallic behaviour above the superconducting transition temperature.Tc (R=0) is observed between 80 and 85 K. Annealing temperature has a profound effect onTc (R=0) and on the orientation of the film. Annealing in air in near-melting region yields highly oriented films withc-axis perpendicular to the substrate. These films show a sharp superconducting transition with zero resistance at 85 K. Microbridges of the dimensions of 50 µm × 50 µm have been patterned photolithographically followed with chemical etching. The 1 V characteristics of the microbridges show Josephson effects due to the presence of grain boundary weaklinks. The temperature dependence of the critical current for these microbridges suggest formation of superconductor-normal-superconductor type weaklinks.

    • Author Affiliations

       

      D K Walia1 A K Gupta1 G S N Reddy1 V N Ojha1 V S Tomar1 Neeraj Khare1 N D Kataria1 K C Nagpal1

      1. Cryogenics Division, National Physical Laboratory, Dr K S Krishnan Road, New Delhi - 110 012, India
    • Dates

       
  • Bulletin of Materials Science | News

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