DC-SQUIDs and flux transformers in YBa/sub 2/Cu/sub 3/O/sub 7/ magnetometers at 77 K

Author

Schilling, M. ; Scharnweber, R. ; Volkl, S.

Author_Institution

Inst. fur Angewandte Phys., Hamburg Univ., Germany

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2346

Lastpage

2349

Abstract

For biomagnetic applications magnetometer devices are prepared in a multilayer process based on KrF-excimer laser deposition of superconductor and insulator layers as well as semiconducting barriers. For patterning conventional photolithography and argon-ion etching are used. In the DC-SQUIDs we employ Josephson junctions with artificial barriers of PrBa/sub 2/Cu/sub 3/O/sub 7/ in a ramp-type geometry. As insulating layers in the flux transformers we use SrTiO/sub 3/. Both, the DC-SQUIDs and the input-coils operate up to temperatures of 86 K. The characterisation of the devices is made by electrical transport and by noise measurements. For the use as sensitive magnetometers the DC SQUIDs are either used in inductively shunted magnetometers with galvanic coupling to a large pick-up coil or are coupled to flux transformers in a flip-chip arrangement.<>

Keywords

Josephson effect; SQUID magnetometers; barium compounds; flip-chip devices; high-temperature superconductors; laser deposition; photolithography; superconducting device noise; superconducting device testing; yttrium compounds; 77 to 86 K; Ar ion etching; DC SQUIDs; HTSC magnetometers; Josephson junctions; KrF; KrF excimer laser deposition; PrBa/sub 2/Cu/sub 3/O/sub 7/ artificial barriers; SrTiO/sub 3/ insulating layers; YBa/sub 2/Cu/sub 3/O/sub 7/-PrBa/sub 2/Cu/sub 3/O/sub 7/; YBa/sub 2/Cu/sub 3/O/sub 7/-SrTiO/sub 3/; characterisation; electrical transport measurements; flip-chip arrangement; flux transformers; galvanic coupling; inductively shunted magnetometers; multilayer process; noise measurements; patterning; photolithography; ramp-type geometry; Biomagnetics; Couplings; Josephson junctions; Lithography; Magnetic multilayers; Power transformer insulation; SQUID magnetometers; Semiconductivity; Semiconductor lasers; Superconducting epitaxial layers;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403056

Filename

403056