Title :
Characteristics of high critical current density Josephson junctions with Nb/AlO/sub x//Nb trilayers
Author :
Sugiyama, H. ; Fujimaki, A. ; Hayakawa, H.
Author_Institution :
Dept. of Quantum Eng., Nagoya Univ., Japan
fDate :
6/1/1995 12:00:00 AM
Abstract :
We fabricated high critical current density (high J/sub c/) Josephson junctions, up to 47 kA/cm/sup 2/, consisting of Nb/AlO/sub x//Nb trilayers by use of high vacuum dc magnetron sputtering (less than 10/sup -6/ Pa). The relationship Jc/spl prop/(Pt)/sup -0.5/ can be obtained up to 47 kA/cm/sup 2/, where P and t are pressure and time, respectively, in oxidizing an Al surface. In the high J/sub c/ junctions, microshorts existed in Al surfaces. A property peculiar to most of the high J/sub c/ junctions was a step appearing at 1/3 gap voltage on their I-V curves. Magnetic field dependence of this step was different from that of a Fiske step.<>
Keywords :
Josephson effect; aluminium compounds; critical current density (superconductivity); niobium; sputter deposition; superconducting device testing; superconducting junction devices; 1 muPa; Al; Al surface oxidation; I-V curves; Josephson junctions; Nb-AlO-Nb; Nb/AlO/sub x//Nb trilayers; current steps; gap voltage; high critical current density; high vacuum DC magnetron sputtering; magnetic field dependence; microshorts; Argon; Artificial intelligence; Critical current density; Elementary particle vacuum; Fabrication; Josephson junctions; Logic devices; Niobium; Oxidation; Sputtering;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
