Version 7/21/01 current-perpendicular-to-plane (CPP) magnetoresistance

Giant magnetoresistance (GMR) in magnetic multilayers composed of alternating layers of ferromagnetic (F) and non-magnetic (N) metals is of both fundamental and technological interest. Technologically, GMR is already being used for sensors and read-heads. Scientifically, much has been learned about the physics underlying GMR, but new insights are still being generated. We, describe some important information learned about GMR from measurements in the current-perpendicular to-plane (CPP) geometry. This geometry has the attractive features that the CPP-MR is often larger than the more usual current-in plane (CIP)-MR, and often allows more direct access to the physics underlying GMR. Topics covered include: anisotropic scattering in F-layers and at F/N interfaces, spin-memory-loss within F- and N-metal layers and at interfaces, whether mean-free-paths are scaling lengths in the CPP-MR, and current-driven magnon excitation and magnetization reversal. (C) 2002 Elsevier Science B.V. All rights reserved.