Title :
Fabrication of biepitaxial YBCO Josephson junctions on different substrates
Author :
Petersen, K. ; Stolzel, C. ; Schmitt, M. ; Krimmer, C. ; Wilkens, W. ; Sollner, J. ; Grueninger, H.W. ; Adrian, H.
Author_Institution :
Daimler-Benz Forschungsinst., Frankfurt/Main, Germany
fDate :
6/1/1995 12:00:00 AM
Abstract :
Biepitaxial Josephson junctions were fabricated on MgO and SrTiO/sub 3/ (STO) substrates. Electrical characteristics such as the critical current densities J/sub c/, contact resistivities /spl rho//sub n/ and I/sub c/R/sub n/-products on both substrates are investigated. Junctions on MgO substrates are stable against thermal cycling in contrast to many junctions on STO substrates. The obtained current-voltage characteristics and Shapiro step oscillations are in agreement with the RSJ-model. The resistive transitions are strongly broadened. DC-SQUIDs patterned on both substrates show modulations dV/d/spl Phi/ at 77 K. At 55 K the energy resolution /spl epsi/ in the range of white noise lies within a factor of two of the theoretical limit.<>
Keywords :
Josephson effect; SQUIDs; barium compounds; contact resistance; critical current density (superconductivity); high-temperature superconductors; superconducting device noise; superconducting device testing; white noise; yttrium compounds; 55 K; 77 K; DC-SQUIDs; MgO; RSJ-model; Shapiro step oscillations; SrTiO/sub 3/; YBaCuO-MgO; YBaCuO-SrTiO/sub 3/; biepitaxial Josephson junctions; contact resistivities; critical current densities; current-voltage characteristics; energy resolution; resistive transitions; resistively shunted junction; thermal cycling; white noise; Conductivity; Contacts; Critical current density; Current-voltage characteristics; Electric variables; Energy resolution; Fabrication; Josephson junctions; White noise; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
