Magnetic shielding properties and transport currents of oxide superconductors

✍ Scribed by A. Yahara; H. Matsuba

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 351 KB
• Volume: 29
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(89)90198-7

✦ Synopsis

We have measured the magnetic flux in YBa2Cu30F superconductors when transport currents were allowed to flow in zero external field at 77 K. The magnetic flux was trapped when the transport current exceeded a value /cs, which was smaller than the transport critical current let; typically, 0.4/ct. We have also measured the critical shielding flux density Bol as a function of the transport current supplied to the shielding specimens. With increasing transport current, Bol decreased due to the self-field and diminished to zero at the current /cs. Owing to the difference in superconducting properties of different substructures in the specimen, the shielding critical current/es is believed to be determined by the part of the substructure with the lowest critical currents, and the transport critical current/ct is thought to be determined by the part of the substructure with the highest critical currents in the sample. The estimated value of Bol with Ic,, derived from the Bean-London critical state model, agreed with the measured value Bol.