YBa/sub 2/Cu/sub 3/O/sub 7-x/ Josephson junctions on bicrystal Al/sub 2/O/sub 3/ and SrTiO/sub 3/ substrates

Author

Vale, L.R. ; Ono, R.H. ; Rudman, D.A.

Author_Institution

Nat. Inst. of Stand. & Technol., Boulder, CO, USA

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3193

Lastpage

3196

Abstract

Bicrystal grain-boundary junctions (bi-GBJs) have been reproducibly fabricated on SrTiO/sub 3/ (STO) and r-plane Al/sub 2/O/sub 3/ (sapphire) bicrystal substrates. Sapphire bicrystals are candidates for high-frequency applications due to their low dielectric constant and loss tangent. The sapphire bi-GBJs demonstrated resistively shunted junction (RSJ)-like current voltage characteristics, with junction parameters comparable to the STO bi-GBJs and critical current densities Jc/spl sim/10/sup 5/ A/cm/sup 2/. Independent control of junction resistance (R/sub N/) was demonstrated with the use of Au shunt layers. In addition, overlayers such as Au or STO may act to passivate the GBJs and improve long term stability.

Keywords

Josephson effect; barium compounds; bicrystals; critical current density (superconductivity); grain boundaries; high-temperature superconductors; sapphire; strontium compounds; yttrium compounds; Al/sub 2/O/sub 3/; Au; Au shunt layer; STO substrate; SrTiO/sub 3/; YBa/sub 2/Cu/sub 3/O/sub 7-x/ Josephson junction; YBa/sub 2/Cu/sub 3/O/sub 7/; bicrystal grain boundary junction; critical current density; current voltage characteristics; dielectric constant; dielectric loss tangent; high-frequency applications; normal resistance; passivation; resistively shunted junction; sapphire substrate; stability; Annealing; Critical current; Dielectric substrates; Frequency; Grain boundaries; Josephson junctions; Mixers; Pulsed laser deposition; Voltage; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.622009

Filename

622009