Critical current and Josephson properties of single grain boundary in BaPb1-xBixO3 bicrystals

✍ Scribed by V. Stepankin; A.V. Kuznetsov

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 419 KB
• Volume: 33
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(93)90053-q

✦ Synopsis

he critical current and transport properties of the single grain boundary in bulk bicrystals of the oxide superconductor BaPbl_xBi~O3 were measured. The I-V characteristic clearly shows a Josephson supercurrent and a system of self-excited current resonances, and the measured critical current oscillates in an applied magnetic field. Estimates of the Josephson junction size, based on the period of these oscillations, gives values close to the geometric size of a single grain boundary and we conclude that the grain boundary is single and an unbroken Josephson barrier exists, with some inhomogeneities in the spatial distribution of the critical current. The temperature dependence of the grain boundary junction critical current was investigated, including effects of thermally activated phase slippage. The temperature dependence of the critical current (without reduction due to fluctuations) in terms of the power law I c= (1 -T/Tc) 16 near the critical temperature was evaluated by resistive transition analysis.