Key points are not available for this paper at this time.
The temperature dependence of the magnetic penetration depth is determined directly from low-field dc magnetization measurements on single-crystal Y-Ba-Cu-O (T₂=89. 7 K, T₂=0. 2 K). The results are consistent with the behavior expected from a BCS (s wave) superconductor.
Krusin‐Elbaum et al. (Mon,) studied this question.