Reversible magnetization in YBaCuO ceramics

✍ Scribed by G. Triscone; B. Revaz; A.F. Khoder; J.-Y. Genoud; A. Junod; J. Muller

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 184 KB
• Volume: 235-240
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)92004-4

✦ Synopsis

We have investigated the reversible magnetization M(T,H) of YBaCuO ceramics. "7~e three superconducting phases of this system (Y-123: YBa2Cu307; Y-247:YzBanCu7015 and Y-124: YBa2Cu4Os) present a small reversible regime below To extending over 10 to 25 K, depending on the external magr~euc field (3 to 55 kOe, respectively). Within these temperature and field limits, the magnetization can bc described satisfactorily by the London model. Using additionally the Werthamer-Helfand-Hohenberg (WHH) tc ~nperature dependence for He2(T) and the 2-fluid parabolic law for He(T), a fit of all reversible data yaelds 0Hezd0T I --4.3 T/K, ~ab(O)=lO 8/~, and L~(0)=1650/~ for the Y-123 phase. The critical field appears to be signtficantly higher than that obtained by other methods. Lower critical fields are obtained for Y-124, and intermediate values are found for Y-247, as expected from its crystallographic structure that consists of alternating blocks of Y-123 and Y-124.