Fabrication of YBa/sub 2/Cu/sub 3/O/sub 7/ ramp-type junctions by interface treatments

Author

Dittmann, R. ; Heinsohn, J.-K. ; Braginski, A.I. ; Jia, C.L.

Author_Institution

Inst. fur Schicht- und Ionentech., Forschungszentrum Julich GmbH, Germany

Volume

9

Issue

2

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

3440

Lastpage

3443

Abstract

We have investigated ramp-type junctions with barriers fabricated by interface treatments instead of epitaxially grown barrier layers. In our approach, YBa/sub 2/Cu/sub 3/O/sub 7/ ramps were treated with Ar ions in a Kaufmann-type source and subsequently annealed prior to the deposition of the top electrode. The I-V curves of the junctions as well as the power dependence of the Shapiro step height can be well described by the RSJ-model. At 77 K the critical current density is 10 kA/cm/sup 2/, and the critical voltage is about 30 /spl mu/V. The strong modulation of the critical current with external magnetic field indicates the formation of a homogeneous barrier layer at the interface. The temperature dependence of critical current and normal resistance suggests a metallic barrier as interface layer.

Keywords

Josephson effect; annealing; barium compounds; high-temperature superconductors; sputter etching; yttrium compounds; Ar ion beam etching; I-V characteristics; RSJ model; Shapiro step height; YBa/sub 2/Cu/sub 3/O/sub 7/; YBa/sub 2/Cu/sub 3/O/sub 7/ ramp-type Josephson junction; annealing; barrier fabrication; critical current density; critical voltage; interface treatment; magnetic field modulation; metallic barrier; normal resistance; temperature dependence; Annealing; Argon; Critical current; Critical current density; Electrodes; Fabrication; Magnetic fields; Magnetic modulators; Temperature dependence; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.783769

Filename

783769