Field effects on the dielectric property of YBCO bicrystal grain boundary junctions

Author

Nakajima, K. ; Yokota, K. ; Myoren, H. ; Chen, J. ; Yamashita, T.

Author_Institution

Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2861

Lastpage

2864

Abstract

Electric field effects on YBCO grain boundary Josephson junctions combined with inverted MIS (Metal, Insulator, Superconductor) structures were studied. Current steps and hysteresis recognized in current-voltage curves were strongly affected by the field. The current steps were attributed to the self-excited resonances, i.e., Fiske steps. Both the effects were interpreted by the field dependence of the effective dielectric constant of the grain boundary which has a certain contribution from the large dielectric constant of SrTiO/sub 3/ substrates. The effective dielectric constant normalized with barrier thickness of the junction was estimated to be about 40 nm/sup -1/ for the zero gate voltage and was decreased by a factor of 2 with the electric field of /spl plusmn/16 kV/cm. This feature is assumed adequate for tuning the phase velocity in the bicrystal grain boundaries.<>

Keywords

Josephson effect; barium compounds; electric field effects; flux flow; grain boundaries; high-temperature superconductors; penetration depth (superconductivity); permittivity; superconducting device testing; yttrium compounds; Fiske steps; Josephson junctions; SrTiO/sub 3/; YBa/sub 2/Cu/sub 3/O/sub 7/-SrTiO/sub 3/; barrier thickness; bicrystal grain boundary junctions; current-voltage curves; dielectric property; effective dielectric constant; electric field effects; inverted MIS structures; phase velocity; self-excited resonances; zero gate voltage; Dielectric constant; Dielectric substrates; Dielectrics and electrical insulation; Grain boundaries; Hysteresis; Josephson junctions; Metal-insulator structures; Resonance; Voltage; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403188

Filename

403188