Title :
YBa/sub 2/Cu/sub 3/O/sub 7/(-x) step-edge junctions prepared on sapphire substrates with YSZ buffer layer
Author :
Adam, R. ; Benacka, S. ; Chromik, S. ; Darula, M. ; Strbik, V. ; Gazi, S. ; Kostic, R. ; Pincik, E.
Author_Institution :
Inst. of Electr. Eng., Acad. of Sci., Bratislava, Slovakia
fDate :
6/1/1995 12:00:00 AM
Abstract :
Electrical properties of YBa/sub 2/Cu/sub 3/O/sub 7-x/(YBCO) step-edge junctions were investigated. Steps of height approximately 90 nm were prepared on sapphire substrates by Ar milling. Step angles were adjusted by the angle of incidence of Ar ions. After vacuum deposition of the YSZ buffer layer (50 nm thick) an epitaxial YBCO film was grown by magnetron sputtering. Step edge junctions were prepared by wet etching. The current-voltage characteristics were of RSJ type, with I/sub c/R/sub n//spl ap/0.5 mV at 77 and Shapiro steps were observed up to 0.2 mV (at 9.2 GHz in the temperature range 4.2-80 K) and compared with the resistively shunted Josephson junction (RSJ) model including capacitance and noise.<>
Keywords :
Josephson effect; barium compounds; etching; high-temperature superconductors; sputter deposition; superconducting device noise; superconducting device testing; superconducting epitaxial layers; superconducting junction devices; vapour phase epitaxial growth; yttrium compounds; 0.2 mV; 4.2 to 80 K; 50 nm; 77 K; 9.2 GHz; 90 nm; Al/sub 2/O/sub 3/; Ar milling; RSJ type I-V characteristics; Shapiro steps; Y/sub 2/O/sub 3/ZrO/sub 2/; YBa/sub 2/Cu/sub 3/O/sub 7-x/ step-edge junctions; YBa/sub 2/Cu/sub 3/O/sub 7/; YSZ buffer layer; capacitance; current-voltage characteristics; electrical properties; epitaxial YBCO film; magnetron sputtering; microwave irradiation; noise; resistively shunted Josephson junction model; sapphire substrates; step angles; step height; vacuum deposition; weak link structures; wet etching; Argon; Buffer layers; Current-voltage characteristics; Josephson junctions; Milling; Sputtering; Substrates; Temperature distribution; Wet etching; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
