Finite size effect in Bi2Sr2CaCu2O(8+d) and YBa2Cu3O6.7 probed by the in-plane and out of plane penetration depths

T. Schneider; D. Di Castro

doi:10.1103/PhysRevB.69.024502

paper

Finite size effect in Bi2Sr2CaCu2O(8+d) and YBa2Cu3O6.7 probed by the in-plane and out of plane penetration depths

arXiv:cond-mat/0309064 · doi:10.1103/PhysRevB.69.024502

Abstract

We report on a systematic finite size scaling analysis of in-plane penetration depth data taken on Bi $_{2}$ Sr $_{2}$ CaCu $_{2}$ O $_{8 + δ}$ epitaxially-grown films and single crystals, and of in-plane and out of plane data taken on YBa $_{2}$ Cu $_{3}$ O $_{6.7}$ aligned powder. It is shown that the tails in temperature dependence of the penetration depths, appearing around the transition temperature, are fully consistent with a finite size effect. This uncovers the granular nature of these cuprates, consisting of superconducting homogeneous domains of nanoscale extent, embedded in a non-superconducting matrix.

9 pages, 8 figures