▎ 摘　　要

In this paper the impact of repetition of graphene-based ferromagnet-normal(FN) regions on the transport properties of system is studied, theoretically. Here, the purpose is to generalize the Fert-Grunberg FNF multijunction to a graphene-based one. Thus, parallel and antiparallel magnetization alignments of ferromagnetic regions are considered. The concept of quantum well is used to calculate the transmission probability using the Dirac-Bogoliubov-de Gennes equations. Charge, spin and thermal conductances are investigated for multilayer junctions in terms of magnetization alignments, strength of ferromagnets and thickness of ferromagnet regions. Finally charge, spin and thermal Giant magnetoresistances (GMR) are calculated for the above-mentioned structures, It is obtained that the spin conductance of antiparallel setups is zero, thus it can be used as a spin valve. (C) 2015 Elsevier By. All rights reserved,