HYSTERESIS OF THE TRANSPORT CRITICAL-CURRENT OF (TL,PB)-(SR,BA)-CA-CU-O AND BI-SR-CA-CU-O CONDUCTORS - EFFECTS OF TEMPERATURE AND MAGNETIC-FIELD

The transport critical current (I-c) of polycrystalline (Tl0.5Pb0.5)(S r0.8Ba0.2)(2)Ca2Cu3Ox (Tl1223) and Bi2Sr2CaCu2Ox (Bi2212) conductors h as been determined for a range of temperature (25-77.3 K) and a range of externally applied magnetic field (H-app = 0-1.5 T). Hysteresis of the I-c versus H-app behavior has been observed for the Tl1223 conduct or and has been interpreted using Bean's critical state model [1]. For the Tl1223 conductor, the remnant critical current measured for H-app = 0 after exposure to 1.5 T was found to be independent of temperatur e. This behavior has been shown to be consistent with the critical sta te model. No hysteresis of I-c versus H-app was detectable for the Bi2 212 conductor.