Title :
Transport processes and reduction of I/sub c/R/sub n/ product in YBa/sub 2/Cu/sub 3/O/sub x//PrBa/sub 2/Cu/sub 3/O/sub x//YBa/sub 2/Cu/sub 3/O/sub x/ ramp-type Josephson junctions
Author :
Boguslavskij, Y.M. ; Gao, J. ; Rijnders, A.J.H.M. ; Terpstra, D. ; Gerritsma, G.J. ; Rogalla, H.
Author_Institution :
Fac. of Appl. Phys., Twente Univ., Enschede, Netherlands
fDate :
3/1/1993 12:00:00 AM
Abstract :
The mechanisms of current passage and the causes of I/sub c/R/sub n/ (critical-current normal-resistance) product reduction of YBCO/PBCO/YBCO ramp-type junctions are analyzed. At PBCO (PrBa/sub 2/Cu/sub 3/O/sub x/) barrier thicknesses L=8-20 nm the junction characteristics are determined by the thickness of the PBCO barrier and its nature. The boundary resistance and depression of the YBCO (YBa/sub 2/Cu/sub 3/O/sub x/) superconducting parameters near the interface do not strongly affect the junction parameters. The behaviour of the YBCO/PBCO/YBCO junctions cannot be described by simple SNS (superconductor-normal metal-superconductor) weak-link or SIS (superconductor-insulator-superconductor) tunnel models. A strong pair-breaking effect and a one-center inelastic tunneling process are taken into account to explain the Josephson and normal state characteristics of these junctions.<>
Keywords :
Cooper pairs; Josephson effect; barium compounds; critical currents; high-temperature superconductors; praseodymium compounds; superconducting junction devices; yttrium compounds; HTSC; YBa/sub 2/Cu/sub 3/O/sub x/-PrBa/sub 2/Cu/sub 3/O/sub x/-YBa/sub 2/Cu/sub 3/O/sub x/ junctions; boundary resistance; critical current normal resistance product; current passage; normal state characteristics; one-center inelastic tunneling process; pair-breaking effect; ramp-type Josephson junctions; Critical current density; Electrodes; Epitaxial growth; Etching; High temperature superconductors; Josephson junctions; Physics; Surface cleaning; Temperature dependence; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
