Improvement of transport critical current density in in-situ synthesized silver-sheathed superconducting tape of Tl0.78Bi0.22Sr1.6Ba0.4Ca2Cu3O9−δ by intermediate annealing and pressing

✍ Scribed by Z.F. Ren; C.A. Wang; J.H. Wang; D.J. Miller; K.C. Goretta

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 393 KB
• Volume: 247
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00185-9

✦ Synopsis

Intermediate thermal annealing and static hydraulic pressing were applied to process in-situ synthesized silver-sheathed superconducting Tlo.78Bio.22Srl.6Bao.4Ca2Cu309_ 8 tapes. It was found that this intermediate processing improved the tape performance as indicated by a 65% increase of transport critical current density (J~) at zero field and an even greater increase of 340% at 5.5 T. Scanning and transmission electron microscopy (SEM and TEM, respectively) and X-ray diffraction (XRD) were used to characterize the microstructural differences and phase formation of the tapes prepared by three different methods. It was found that a higher core density and more favorable pore distribution due to the intermediate processing were the main reasons for the improvement in J¢. Field-cooled (FC, B = 50 G) magnetization measurements using a Superconducting Quantum Interference Device (SQUID) demonstrated a better flux pinning for the tape subjected to the intermediate processing, which is consistent with the greater improvement of the transport Jc at 5.5 T than at zero field.