Magneto-optical studies of high-T/sub c/ SQUID circuits

Author

Govorkov, S. ; Fife, A.A. ; Anderson, G. ; Haid, V. ; Hu Zhou ; Heinrich, B. ; Chrzanowski, J.

Author_Institution

CTF Syst. Inc., Port Coquitlam, BC, Canada

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3235

Lastpage

3239

Abstract

Magneto-optical studies have been carried out on high-T/sub c/ thin film circuits such as flux transformer coils and DC SQUIDs. The high resolution magnetic field maps emphasize regions of high field and localized defects. Observation of the flux transformer coil response to an applied field allowed a determination of the minimum critical current. An inversion procedure is also described for calculation of the current distributions in the patterned coil films. The images of DC SQUIDs fabricated on bicrystal substrates show the effects of flux penetration through the bicrystal boundary. The noise performance of the coils while flip-chip coupled to the bicrystal DC SQUIDs is also summarized. The research has provided information useful for improvements to multi-level high-T/sub c/ circuit design and fabrication.

Keywords

SQUIDs; barium compounds; critical currents; current distribution; flaw detection; flip-chip devices; high-temperature superconductors; magnetic field measurement; magneto-optical devices; superconducting device noise; superconducting device testing; superconducting transformers; superconductor-insulator-superconductor devices; yttrium compounds; DC SQUIDs; YBa/sub 2/Cu/sub 3/O/sub 7/-SrTiO/sub 3/-YBa/sub 2/Cu/sub 3/O/sub 7/; bicrystal substrates; current distributions; flip-chip coupling; flux penetration; flux transformer coils; high field regions; high resolution magnetic field maps; high-T/sub c/ SQUID circuits; inversion procedure; localized defects; magneto-optical studies; minimum critical current; multi-level high-T/sub c/ circuit design; noise performance; patterned coil films; Circuit noise; Coils; Critical current; Current distribution; Magnetic fields; Magnetic films; Magnetooptic effects; SQUIDs; Substrates; Thin film circuits;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.622038

Filename

622038