Irreversibility temperature and meissner fraction in high temperature superconductors

✍ Scribed by S.B. Ota; G.P. Rapson; P.A.J. De Groot

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 268 KB
• Volume: 165-166
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/s0921-4526(09)80158-0

✦ Synopsis

Low field «3OmT) magnetisation measurements have been carried out on BSCCO and YBCO ceramics and on BSCCO single crystals. The Meissner fraction (MF) has been found to obey a power law: MF ~H.-m where H. is the internal field. The value of m is different for the different samples. The fi~ld range o~er which the power law holds and m increase with temperature. The ihreversibility temperature (T.) determined by a fixed criterion oM, obeys the relation: (T -T.) ~H .. In the case of BSCCO, n in~reases as oM increases. We argue that present flux pinning mOdeis do ~ot explain these results.