Magnetic Tunneling Effect

Spin-polarized electron tunneling between ferromagnetic metal layers is a phenomenon of considerable interest. The tunneling conductance changes with the angle between the magnetization vectors of these ferromagnetic layers (the magnetic valve effect). Although only a small number of experiments on the magnetic valve effect have been reported, it poses interesting possibilities from the standpoint of both basic material science and of applications. This paper reviews briefly the literature on the magnetic valve effect, including some theories and experiments on ferromagnetic tunneling junctions, ferromagnetic multilayer films and ferromagnetic double-layer films.