Spin-filter magnetoresistance in magnetic barrier junctions

The tunnel current and magneto resistance (TMR) are investigated in magnetic tunnel junctions consisting of a spinfilter tunnel barrier, sandwiched between a ferromagnetic (FM) electrode and a nonmagnetic electrode. The investigations are based on the transfer matrix method and the free-electron approximation. The numerical results show that the spin transport depends on the relative magnetization orientation of the FM electrode and the spin-filter barrier, such that the tunnel current reaches its maximum when the magnetic moments of the FM electrode and the magnetic barrier are parallel. It is also found that the TMR increases with increasing the applied voltage. (C) 2003 Elsevier B.V. All rights reserved.