Current and field distributions in superconducting films: determination of critical current by local field measurement

✍ Scribed by Yu.A. Fedorov; V.G. Fleisher; M.G. Semenchenko

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 694 KB
• Volume: 217
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90794-q

✦ Synopsis

The current J and magnetic field H distributions in a thin film have been calculated for arbitrary changes of the external field (He). A joint solution of equations describing the field and current distributions in three different states (Meiuner, critical and mixed) taking into account a tangential field has been found. The decrease of the external field leads to the appearance of the mixed state with a current less than the critical one (J<J©). A simple method for deriving the function Jc(H) from the experimental dependence Hp(Ho) (Hpfthe normal field in the centre of the film) has been suggested. An example given for a thin ceramic disk shows good agreement of magnetic and transport J¢ values at Ho=0. The hysteresis loops Hp(H°) calculated on the basis of the functions Jc(H) found for a ceramic disk and a thin trim fitted well with the experimental data.