Transport critical current characteristics of Ag/B(P)SCCO tapes in magnetic field

✍ Scribed by S.R. Shukla; R.G. Sharma

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 586 KB
• Volume: 247
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00186-7

✦ Synopsis

Silver-sheathed Bil.7Pbo.4Sr2Ca2Cu3Ox (Ag/B(P)SCCO) tapes have been prepared by powder-in-tube (PIT) technique in which a process of repeated rolling and intermediate sintering has been followed. The critical current density (Je) has been measured at 4.2 K in magnetic field up to 4.4 T at every stage. An increasing grain alignment and compaction is achieved with decreasing oxide core thickness (to), as revealed by SEM studies. The inverse dependence of Jc on t o of the tape specimens can be understood in terms of surface pinning. The J¢ variation in the magnetic field (B) is found to obey the B -°5 type of dependence at 4.2 K. Consequently, the observed linear relationship between volume pinning force (Fp) and B °'s is indicative of flux-pinning controlled Jc rather than weak-link controlled. An attempt has been made to explain the magnetic field dependence of F~ in terms of Kramer's theory. Using this theory we are able to make a rough estimate of the characteristic scaling field (B) at 4.2 K for various tape specimens.