1. Home
    2. Journals
    3. Bulletin of Materials Science
    4. Volume 14
    5. Issue 3

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/boms/014/03/0681-0686

    • Keywords

       

      Positron annihilation; Doppler broadening

    • Abstract

       

      Doppler-broadened annihilation radiation spectra have been measured as a function of temperature from 77 K to 300 K, for several high temperature oxide superconductors viz single-phase YBCO, single- and mixed-phase Tl-Ca-Ba-Cu-O and Bi-Ca-Sr-Cu-O compounds. The temperature-dependent parameters extracted respond to a change at the onset of superconducting transition. The observations point to involvement of oxygen valence electrons at the onset of superconducting transition. Also a possible structural change and/or increase in electron density at the oxygen vacancy/defect sites seem to accompany the transition. In addition, the parameters derived are seen to be sensitive to the presence of more than one superconducting phases in mixed phase samples.

    • Author Affiliations

       

      P K Pujari1 T Datta1 Satya Prakash1 S B Manohar1 I K Gopalakrishnan1 G M Phatak1 J V Yakhmi1 PVPSS Sastry1 R M Iyer1

      1. Chemical Group, Bhabha Atomic Research Centre, Bombay - 400 085, India

    • Dates

       
      Published
      June 1991

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.

Contact | Site index