Eur. Phys. J. B 42, 187-191 (2004)
https://doi.org/10.1140/epjb/e2004-00371-x

Temperature and voltage dependence of magnetic barrier junctions with a nonmagnetic spacer

¹ Department of Physics, Sharif University of Technology, 11365-9161, Tehran, Iran
² Department of Physics, Tehran Payame Noor University, Fallahpour St., Nejatollahi St., Tehran, Iran

Corresponding authors: ^a aashokri@mehr.sharif.edu - ^b a-saffar@tehran.pnu.ac.ir

Received: 25 June 2004
Published online: 14 December 2004

Abstract

The temperature and voltage dependence of spin transport is theoretically investigated in a new type of magnetic tunnel junction, which consists of two ferromagnetic outer electrodes separated by a ferromagnetic barrier and a nonmagnetic (NM) metallic spacer. The effect of spin fluctuation in magnetic barrier, which plays an important role at finite temperature, is included by taking the mean-field approximation. It is found that, the tunnel magnetoresistance (TMR) and the electron-spin polarization depend strongly on the temperature and the applied voltage. The TMR and spin polarization at different temperatures show an oscillatory behavior as a function of the NM spacer thickness. Also, the amplitude of these oscillations is regularly reduced when the temperature increases. The maximum TMR value, varies approximately from 270% in reverse bias (at T=0 K) to 25% in forward bias (at ).