SOME PROPERTIES OF HONEYCOMB-TYPE BI1.6PB0.4SR2CA3CU4OY SUPERCONDUCTORS


NEZIR S., KARAL H., KUCUKOMEROGLU T. , VIDADI Y., ALTUNBAS M.

JOURNAL OF ALLOYS AND COMPOUNDS, vol.218, no.1, pp.47-50, 1995 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 218 Issue: 1
  • Publication Date: 1995
  • Doi Number: 10.1016/0925-8388(94)01345-4
  • Title of Journal : JOURNAL OF ALLOYS AND COMPOUNDS
  • Page Numbers: pp.47-50

Abstract

A Bi-based superconductor of nominal composition Bi1.6Pb0.4Sr2Ca3Cu4Oy was prepared using Bi2O3, PbO, SrCO3, CaO and CuO powders and liquid ammonium nitrate as solvent and homogenizer. For comparison, another superconductor with nominal composition Bi1.8Pb0.2Sr2Ca2Cu3Ox was obtained using the same method and conditions. It was observed that the ceramic has a honeycomb granular structure, a transition temperature of 110 K, an increased thermal expansion coefficient (8.7x10(-6) K-1) and a fourfold higher critical current density (25 A cm(-2)). The volume of the sample increased during annealing (for 100 h at 845 degrees C). The phases existing in this new type superconductor were determined. The composition and temperature dependences of phase transition characteristics, resistivity and inductance changes were investigated. The height of the energy barrier separating the metastable local superconducting phase and the normal metallic phase was found to be 0.34 eV in the temperature interval 110 K