• Anjana Asthana

      Articles written in Bulletin of Materials Science

    • Observation of curious spiral growth features in Tl doped Hg bearing high temperature superconducting tapes

      Anjana Asthana O N Srivastava

      More Details Abstract Fulltext PDF

      Synthesis of H𝑔(Tl)Ba2Ca2Cu3O8+𝛿 superconducting tapes have been accomplished by annealing the precursor tape, Ba2Ca2Cu3O𝑦 (fabricated by doctor blade tape casting technique) in an environment of H𝑔(Tl) vapour. Characterization of superconducting HTSC tape sample was carried out through XRD, TEM, SEM and R–T measurements. Surface morphological investigations of the as-synthesized H𝑔(Tl)Ba2Ca2Cu3O8+𝛿 HTSC tapes by scanning electron microscope have shown the occurrence of curious growth characteristics resembling spiral like features. These growth spirals encompass nearly the whole grain suggesting that spiral growth led to the formation of small crystal like grains of superconducting material H𝑔(Tl)Ba2Ca2Cu3O8+𝛿. The likely mechanism for the generation of these screw dislocations has been elucidated in terms of incoherent coalescence of growth fronts formed from H𝑔(Tl):1223 and H𝑔(Tl):1234 nuclei.

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