Critical current densities and irreversibility lines of new oxycarbonate superconductors (Cu0.5C0.5Ba2Can−1CunO2n+3 (n = 3, 4)

✍ Scribed by H. Kumakura; K. Togano; T. Kawashima; E. Takayama-Muromachi

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 305 KB
• Volume: 226
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90198-8

✦ Synopsis

From the hystereses in DC magnetization curves, we estimated critical current densities J¢ and irreversibility fields Bi,~ of (Cuo.5Co.5) Ba2Ca2Cu3Og_+ 6 ( (Cu, C )-1223) and (Cuo.5Co.5) Ba2Ca3Cu4Ol l _+ a ( (Cu, C ) -1234 ) new superconductors, and the data were compared with those values reported for other high-T¢ oxide superconductors. The temperature dependence of Jc in a magnetic field for the (Cu, C)-based oxides is much smaller than that of HgBa2Ca2Cu3Os+~(Hg-1223). At 77 K, Bi~ of (Cu, C)-1234 is 3.8 T which is higher than that of rig-1223 in spite of a lower critical temperature of (Cu, C)-1234. The slopes of the irreversibility lines for (Cu, C )-1223 and (Cu, C)-1234 are steeper than that of Hg-1223. The results suggest that the anisotropy in the (Cu, C)-based oxides seems to be smaller than that of Hg-based oxide although the crystal structure is almost the same for both systems.