Interfacial properties of Fe/Cr multilayers in the current-perpendicular-to-plane geometry

Recent arguments that the Current-Perpendicular-to-Plane (CPP) Magnetoresistance of Fe/Cr multilayers is sensitive to interfacial roughness stimulated us to try to repeat the experiments on which the claims were made. While our CPP specific-resistances are comparable to those previously reported, their detailed behaviors are different. Our data are consistent with a simple two-current series-resistor model with a single enhanced interface resistance 2AR(Fe/Cr)* = 1.6+/-0.15 fOmegam(2), in reasonable agreement with recent calculations. However, our best estimate of the interfacial scattering anisotropy parameter, gamma(Fe/Cr) = -(0.7+/-0.15), is larger in magnitude than predicted by the same calculations. We discuss possible reasons for the differences between our results and previous data. (C) 2002 Elsevier Science B.V. All rights reserved.