Title :
Characterization of grain boundaries in YBa/sub 2/Cu/sub 3/O/sub y/ bicrystal junctions [SQUIDs]
Author :
Hsiao-Wen Yu ; Ming-Jye Chen ; Hong-Chang Yang ; Yang, S.Y. ; Horng, H.E.
Author_Institution :
Dept. of Phys., Nat. Taiwan Univ., Taipei, Taiwan
fDate :
6/1/1999 12:00:00 AM
Abstract :
I-V, V-/spl Phi/ characteristics and atomic force images of grain boundary Josephson junctions fabricated on SrTiO/sub 3/ bicrystal substrates were investigated. The half integer Shapiro steps and I/sub c/ versus B curves show evidence of the inhomogeneous current distribution along the grain boundary junction. The dc SQUID formed on the grain boundary shows the expected V-/spl Phi/ curve. The AFM images, R-T curves and I/sub c/R/sub n/ product reveal sequential destructive deterioration of the junction originating from the underlying grooved substrate. The results are discussed.
Keywords :
Josephson effect; SQUIDs; atomic force microscopy; barium compounds; current distribution; grain boundaries; high-temperature superconductors; yttrium compounds; I-V characteristics; I/sub c/R/sub n/ product; R-T curves; SQUIDs; V-/spl Phi/ characteristics; YBa/sub 2/Cu/sub 3/O; atomic force images; bicrystal junctions; grain boundaries; half integer Shapiro steps; inhomogeneous current distribution; sequential destructive deterioration; underlying grooved substrate; Atomic force microscopy; Grain boundaries; Josephson junctions; SQUIDs; Sputtering; Substrates; Superconducting thin films; Temperature; Thin film devices; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
