Temperature dependence of the anisotropic magnetic penetration depth and lower critical field of single-crystal Pb2Sr2(Y,Ca)Cu3O8+δ

The temperature dependence of the penetration depth of single-crystal Pb2Sr2(Y,Ca)Cu3O8+δ has been determined in the vicinity of Tc (∼75 K) using intermediate-field reversible-magnetization measurements. The ab-plane penetration depth in the restricted region near Tc was found to follow clean-limit BCS behavior from which an estimate of 2575 Å for λab(0) was obtained. The effective-mass anisotropy parameter, γ=(mc/mab)1/2, was found to be 2.5, …