Pinning-Force Density and Critical-Current Density in Superconducting Rb3C60 Fullerene

M. F. Tai ； M. W. Lee

《Chinese Journal of Physics》 34卷2S期 (1996/04) Pp. 657-660

並列摘要

The magnetic critical-current density Jc and the volume-pinning-force density Fp in a well-characterized Rb3C60 fullerene with Tc = 30.3 K have been measured as functions of magnetic field and temperature. They were determined by dc magnetic hysteresis loops at temperatures between 5 and 30 K in an applied field up to 15.5 T. Jc appears to be a monotonically decreasing function of T and H in the temperature and field regions measured. At T = 5 K, Fp initially increases rapidly with increasing field, and it seems to level off when H ＞ 0.5 T, and finally it reaches a saturation value of about 10^10 dyne/cm^3 at H～1.4 T. For T ＞ 5 K, however, Fp(H) appears to peak at a maximum value, Fp,max at field Hp that occurs between 0 and the irreversibility field (Hirr). Both Hp and Fp,max are temperature-dependent and they seem to be proportional to (1－T/Tc)^n.