Giant Magnetoresistance of (001)Fe/(001)Cr Magnetic Superlattices

We have studied the magnetoresistance of (001) Fe/ (001) Cr superlattices prepared by molecularbeam epitaxy. A huge magnetoresistance is found in superlattices with thin Cr layers: For example, with t₂ₑ=9, at T=4. 2 K, the resistivity is lowered by almost a factor of 2 in a magnetic field of 2 T. We ascribe this giant magnetoresistance to spin-dependent transmission of the conduction electrons between Fe layers through Cr layers.