G. Brandstatter et al., EXPERIMENTAL-STUDY OF THE LOWER CRITICAL-FIELD IN HIGH-T-C SINGLE-CRYSTALS, Physica. C, Superconductivity, 282, 1997, pp. 1309-1310
Employing SQUID magnetometry and novel measuring and evaluation techni
ques, precise information on the first penetration field can be obtain
ed and used to extract H-c1. Tl- and Bi-based as well as a series of o
xygen deficient Y-123 high T-c superconducting single crystals were in
vestigated (H/ /c). In all cases, H-c1 is smaller than previously repo
rted and can be described by BCS-theory.