The lower critical fields (Hc1) of Bi2Sr2CaCuO8+d and YBa2Cu3O7-d single crystals were measured by SQUID at various temperatures below Tc. The measurements were based on studies of type-II superconductors in the framework of the modified Kim-Anderson model. Results show that Hc1,c(T) (H∥c axis) and Hc1,ab(T) (H⊥c axis) for BSCCO show an anomalous upturn below about 40 K, but those for YBCO do not show any anomaly.
ASJC Scopus subject areas
- Physics and Astronomy(all)