Title :
Properties of Bi-2212/Bi-22Y2 step-stack Josephson junctions
Author :
Lopera, W. ; Baca, E. ; Gomez, M.E. ; Prieto, P. ; Poppe, U. ; Evers, W.
Author_Institution :
Dept. of Phys., Univ. del Valle, Cali, Colombia
fDate :
6/1/1999 12:00:00 AM
Abstract :
We have fabricated step-stack Josephson junctions based on high quality epitaxial BSCCO (2212 phase) thin films, deposited on Y-doped bismuth (Bi-22Y2) steps. Bi-2212 and Bi-22Y2 films were grown by a high oxygen pressure dc-sputtering technique. The structural characteristics have been analyzed by X-ray, transmission electron microscopy (TEM), and Rutherford backscattering spectrometry (RBS). Bi-22Y2 steps between 100 and 300 nm high were patterned by photolithography and non-aqueous chemical etching. Junctions were characterized by current-voltage (I-V) measurements under magnetic fields and microwave irradiation. I-V curves have shown a clearly hysteretic weak-link Josephson behavior at different temperatures. The temperature dependence of the critical current in these step-stack junctions has also been analyzed.
Keywords :
Josephson effect; bismuth compounds; calcium compounds; high-temperature superconductors; sputtered coatings; strontium compounds; superconducting epitaxial layers; yttrium compounds; BSCCO epitaxial thin film; Bi-2212/Bi-22Y2 step stack Josephson junction; Bi/sub 2/Sr/sub 2/CaCu/sub 2/O-Bi/sub 2/Sr/sub 2/YCu/sub 2/O; DC sputtering; Rutherford backscattering spectrometry; X-ray diffraction; critical current; current-voltage characteristics; magnetic field; microwave irradiation; nonaqueous chemical etching; photolithography; structural characteristics; temperature dependence; transmission electron microscopy; weak link; Backscatter; Bismuth compounds; Chemicals; Josephson junctions; Lithography; Magnetic analysis; Magnetic field measurement; Spectroscopy; Sputtering; Transmission electron microscopy;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
