Magnetic microscopy using SQUIDs

Author

Wellstood, F.C. ; Gim, Y. ; Amar, A. ; Black, R.C. ; Mathai, A.

Author_Institution

Dept. of Phys., Maryland Univ., College Park, MD, USA

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3134

Lastpage

3138

Abstract

SQUID-based magnetic microscopy involves scanning a sample closely past a low-noise SQUID. With the SQUID held in a flux-locked loop, a computer records the feedback output as a function of sample position and converts the resulting data into a false color image of magnetic field strength. Present systems have achieved spatial resolution down to about 5 /spl mu/m and flux resolution down to about 1 /spl mu//spl Phi//sub 0//Hz/sup 1/2/. They have been used to study the pairing symmetry of the high-T/sub c/ superconductors, for high-frequency imaging, and for a variety of applications related studies. Recently, microscopes have also been developed for high resolution magnetic imaging of room-temperature samples. We briefly describe the design, operation, and capabilities of these systems.

Keywords

SQUID magnetometers; microscopy; false color image; flux-locked loop; high-T/sub c/ superconductor; high-frequency imaging; high-resolution imaging; magnetic microscopy; pairing symmetry; room-temperature sample; scanning SQUID microscope; Color; Feedback loop; High-resolution imaging; Image converters; Magnetic fields; Micromagnetics; Output feedback; SQUIDs; Spatial resolution; Superconductivity;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.621996

Filename

621996