| The magnetic coupling in multilayered magnetic structures is of great concern for the last five years. It has been shown that the iron layers separated by the chromium couple antiferromagnetically by several experiments, such as spin-polarized LEED, Brillouin light scattering, ferromagnetic resonance and also magneto-optic Kerr effect. Due to the observed large magnetoresistance in this system, in application, it is also of interest to the magnetoresistive sensor technology. The detailed origin of the magnetic coupling of this system is still unknown. By using angle-resolved photoemission spectroscopy, we observed the direct hybridization of the iron 3d band and Cr 3d band when it is coupled antiferromagnetically. We propose the importance of the spin density wave in Cr. Our model calculation including the spin density wave shows good agreement with the available experimental data. It is different from standard RKKY interaction in that this Cr has spin density wave in it. The overall effect of the spin density wave is to stretch the period of oscillation in exchange interaction. From these results, we conclude that the Cr spin density wave plays a crucial role in the coupling in Fe/Cr/Fe(100) system. |
