THE INTRINSIC CROSSING POINT OF THE MAGNETIZATION VS. TEMPERATURE CURVES IN SUPERCONDUCTING CUPRATES IN THE HIGH-MAGNETIC-FIELD LIMIT

The crossing point of the magnetization vs. temperature curves that ap pears below T-c in highly anisotropic superconducting cuprates was mea sured in different compounds, with a different number, N, of supercond ucting CuO2 layers per periodicity length, s, and also with different values of s. By correcting the measurements from different extrinsic i nhomogeneity effects through the Meissner fraction, it is demonstrated experimentally for the first time that in the high-magnetic-field lim it the intrinsic crossing point may be explained at a quantitative lev el in terms of the Tesanovic and coworkers approach based on thermal f luctuations of quasi-2D vortices (pancakes), with an effective periodi city length equal to s, independently of N.