Weak links in Pb-doped BiSrCaCuO ceramic superconductors

✍ Scribed by P. Svoboda; P. Vašek; O. Smrčková; D. Sýkorová

• Book ID: 103942515
• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 908 KB
• Volume: 167
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(90)90503-7

✦ Synopsis

The dependence of the resistive transition curve R ( T) on measuring current and magnetic field along with AC and DC magnetic susceptibility x(T) has been measured on ceramic superconductors of the nominal composition BiO.,Pb,,sSrCaCul.sOX to elucidate the nature of weak intergranular links in the samples. These weak links are shown to be responsible for pronounced currentdependent resistive tails analogous to those reported for YBaCuO [ 1: 2: 31 ceramics. The A ( T) curves can be interpreted in terms of percolative conduction in a multiphase system with superconducting regions coupled via nonsuperconducting barriers. External magnetic fields below 0.1 mT are shown to be sufficient for partial decoupling of the superconducting grains. A possible role of the Pb atoms in the formation of weak links resulting in a suppression of the transport critical current density J, is discussed.