The intrinsic crossing point of the magnetization vs. temperature curves in superconducting cuprates in the high-magnetic-field limit

¹ Laboratorio de Bajas Temperaturas y Superconductividad, Departamento de Física de la Materia Condensada, Universidad de Santiago de Compostela - E15706 Spain
² Departamento de Cristalografía, Universidad Complutense - E28040 Madrid, Spain
³ Laboratoire de Cristallographie et Sciences des Materiaux, CNRS F14050 Caen Cedex, France
⁴ Instituto de Ciencia de Materiales de Madrid, CSIC - E28049 Cantoblanco, Spain
⁵ Laboratoire de Chimie des Solides, Université Paris XI - F91405 Orsay Cedex, France

Received: 26 January 1998
Accepted: 19 March 1998

Abstract


The crossing point of the magnetization vs. temperature curves that appears below T_c in highly anisotropic superconducting cuprates was measured in different compounds, with a different number, N, of superconducting layers per periodicity length, s, and also with different values of s. By correcting the measurements from different extrinsic inhomogeneity effects through the Meissner fraction, it is demonstrated experimentally for the first time that in the high-magnetic-field limit the intrinsic crossing point may be explained at a quantitative level in terms of the Tesanović and coworkers approach based on thermal fluctuations of quasi-2D vortices (pancakes), with an effective periodicity length equal to s, independently of N.