Resistive transition and perpendicular critical magnetic field in perforated Nb/CuMn multilayers

A peak in the resistance versus temperature measurements,just above T-c, has been observed in Nb/CuMn multilayers with a regular array of holes. The peak is present in zero magnetic field and its height becomes smaller as the perpendicular field is increased. The presence of the peak could be related to the nonhomogeneity of the sample consistently giving an explanation for the upward curvature observed in the H-c2 versus temperature curve. (C) 2000 Elsevier Science B.V, All rights reserved.