Phase evolution, microstructure and transport property of (Bi, Pb)-2223/Ag tapes prepared using powders of varying particle size distribution

• Published in: Superconductor science & technology Vol. 14; no. 6; pp. 417 - 424
• Main Authors: Sobha, A, Aloysius, R P, Guruswamy, P, Syamaprasad, U
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.06.2001; Institute of Physics
• Subjects: Applied sciences; Bi-based cuprates; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical currents; Cuprates superconductors (high tc and insulating parent compounds); Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; High-Tc compounds; Physics; Properties of type I and type II superconductors; Superconducting device characterization, design, and modeling; Superconductivity; Critical current density; Particle size; Inorganic compounds; Transition element compounds; Bismuth oxides; Lead oxides; XRD; Experimental study; Silver; Calcium oxides; Strontium oxides; Transition elements; Superconducting tapes; Superconducting composites; Size effect; High-Tc superconductors; Microstructure; Copper oxides
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/14/6/317

(Bi, Pb)-2223/Ag sheathed tapes were prepared using precursor powders with different particle size distributions which were obtained by grinding the calcined powder for different durations. DTA results revealed that the reaction temperature of the precursor powder depends on the particle size and is at a minimum for the finest powder. Phase evolution studies, transport current measurement at 77 K with and without the application of an external field, microstuctural examination, etc., were carried out in order to evaluate the relative performance of the tapes. Results showed that the particle size has significant effects on the reaction kinetics, ultimate phase fraction, microstructure and transport Jc. For the tapes fabricated using coarser powder, the reaction kinetics were slower and the microstructure contained smaller grains with many misalignments and voids. On the other hand use of fine precursors yielded tapes with a large fraction of secondary phases due to the degradation of the crystallinity of the precursor and a consequent change in the reaction sequence. The tape prepared using a precursor with an average particle size of 3-4 mu m showed the best results with respect to Jc, high-Tc phase fraction, microstructure and Jc-B characteristics. 27 refs.