The role of interfaces in the magnetoresistance of Au/Fe/Au/Fe/GaAs(001)

Authors

Axel Enders, University of Nebraska at LincolnFollow
T. L. Monchesky, Simon–Fraser University
Kenneth Myrtle, Simon–Fraser UniversityFollow
R. Urban, Simon–Fraser University
Brett Heinrich, Simon–Fraser UniversityFollow
Jurgen Kirschner, Max-Planck-Institut für Mikrostrukturphysik, Halle/SaaleFollow
X.-G. Zhang, Oak Ridge National Laboratory
W. H. Butler, Oak Ridge National Laboratory

Date of this Version

6-2001

Comments

Published in J. Appl. Phys., Vol. 89, No. 11, 1 June 2001. Copyright © 2001 American Institute of Physics. Used by permission.

Abstract

The electron transport and magnetoresistance (MR) were investigated in high quality crystalline epitaxial Fe(001) and Au(001) films and exchange coupled Au/Fe/Au/Fe/GaAs(001) trilayer structures. Fits to the experimental data were based on the semiclassical Boltzmann equation, which incorporates the electronic properties obtained from first-principles local density functional calculations. The fits require a surprisingly high asymmetry for the spin dependent electron lifetimes in Fe, τ^↓/ τ^↑ =10 at room temperature. Despite the large atomic terraces at the Au/vacuum and Fe/GaAs interfaces the scattering at the outer interfaces was found to be diffuse. The origin of MR in Au/Fe/Au/Fe/GaAs(001) structures is due to electron channeling in the Au spacer layer. The measured MR is consistent with the diffusivity parameters s^↑=0.55, s^↓=0.77 at the metal–metal interfaces.