A microwave technique for characterization of SNS and grain-boundary junctions

Author

Wosik, J. ; Lei-Ming Xie ; Davis, M.F. ; Wolfe, J.C.

Author_Institution

Texas Center for Supercond., Houston Univ., TX, USA

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2392

Lastpage

2395

Abstract

We have utilized a magnetic field modulated microwave absorption technique for characterizing SNS and grain-boundary junctions. The technique is based on the measurements of the first derivative microwave absorption P, with respect to an applied magnetic field B at 9.5 GHz, as a function of dc magnetic B/sub dc/. A homodyne detection system is used. Due to flux quantization in a non-uniform junction a series of equally spaced microwave absorption lines can be observed for B/sub dc/ and, in strongly coupled junction cases, the dependence of I/sub c/ on magnetic field and temperature can be extracted. Both the intra-grain boundary in a melt-textured YBa/sub 2/Cu/sub 3/O/sub x/ bulk material and thin film single grain boundary junction (GBJ) YBa/sub 2/Cu/sub 3/O/sub x/ were investigated. The result of the measurements agrees with a model in which the grain boundary consists of several sub-junctions in parallel.<>

Keywords

Josephson effect; barium compounds; electromagnetic wave absorption; grain boundaries; high-temperature superconductors; microwave measurement; superconducting thin films; yttrium compounds; 9.5 GHz; SNS junctions; YBa/sub 2/Cu/sub 3/O; critical current; flux quantization; grain-boundary junctions; homodyne detection; intra-grain boundary; magnetic field modulated microwave absorption; melt-textured YBa/sub 2/Cu/sub 3/O/sub x/; nonuniform junction; strongly coupled junction; sub-junctions; thin film YBa/sub 2/Cu/sub 3/O/sub x/; Couplings; Electromagnetic wave absorption; Grain boundaries; Magnetic field measurement; Magnetic fields; Magnetic flux; Magnetic modulators; Microwave measurements; Microwave theory and techniques; Quantization;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403071

Filename

403071