Conductance, magnetoresistance, and interlayer coupling in tunnel junctions modulated by nonmagnetic metallic interlayers

Based on the two-band model and free-electron approximation, we study the magnetism and transport properties of tunnel junctions with nonmagnetic interlayers (NM) between the ferromagnetic electrodes and tunneling barrier. We find that properties of the junctions are intermediate between tunnel junctions and metallic magnetic multilayers. The mean conductance, tunnel magnetoresistance, and interlayer coupling are all the oscillatory functions of the thickness of NM. It suggests that weak antiferromagnetic coupling can be attained by controlling the thickness of NM. Our results have potential in designing spin-polarized tunneling devices with large field sensitivity. (C) 1998 American Institute of Physics.