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    • Keywords


      HighTc superconductors; CaREBaCu3O7−y; fluctuation; excess conductivity

    • Abstract


      The compounds CaREBaCu3O7−y (RE=La and Sm) are tetragonal at room temperature withTc between 60 and 70 K. The single-phase compounds were prepared by solid-state reaction. The resistivity was measured by a four-probe technique in a continuous flow cryostat with the temperature being controlled to an accuracy of 10 mK. The resistivity vs temperature showed a break in slope around 180 K in CaLaBaCu3O7−y and around 220 K in CaSmBaCu3O7−y. The results were analysed for fluctuation conductivity from 180 K downwards. A plot of dρ/dT vsT showed a sharp peak atTm=69·69 K for La compound and 66·00 K for the Sm compound. Detailed analysis of the resistivity in the regionTon to 180 K was carried out using the procedure due to Veira and Vidal. The results are discussed in this paper.

    • Author Affiliations


      H Krishnan1 R Srinivasan1 V Sankaranarayanan1 C K Subramaniam1 G V Subba Rao1

      1. Materials Science Research Centre, Department of Physics, Indian Institute of Technology, Madras - 600 036, India
    • Dates

  • Bulletin of Materials Science | News

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