Abstract
Using the same approach as Camley and Barnas, the author studies theoretically the magnetotransport properties of spin-valve multilayers. He emphasizes that the absolute change in sheet conductance ( Delta G) between parallel and antiparallel alignment of the magnetizations of successive ferromagnetic layers is the most relevant macroscopic quantity to represent and compare the magnetoresistance in these structures. He presents results on the influence of the thicknesses of the ferromagnetic and nonmagnetic layers on the magnetoresistance for the two cases most studied experimentally: sandwiches and multilayers with a large number of periods. He also investigates the influence of the number of periods on the magnetoresistance and discusses the similarities and differences obtained in the respective cases of bulk or interfacial spin-dependent scattering.