Magnetoresistance and Interlayer Exchange Coupling in Ferromagnetic/Nonmagnetic/Insulator (Semiconductor) /Ferromagnetic Tunnel Junctions

Based on the two-band model and free-electron approximation, a treatment of the magnetoresistance (MR) and interlayer exchange coupling (IEC) for ferromagnetic/nonmagnetic/insulator (semiconductor)/ferromagnetic tunnel junctions is presented. It is found that properties of the junctions are intermediate between tunnel junctions and metallic magnetic multilayers. The MR and IEC are all the oscillatory functions of the thickness of nonmagnetic layer. The results have potential in designing spin-polarized tunneling devices with large field-sensitivity.