Oscillatory behavior of the magnetoresistance versus Cu spacer thickness in UHV-grown Co / Cu(111) multilayers

The magnetoresistance of Au 3 /Cu 0.3 / Co 1.2 /Cu t /Co 1.2 /Cu 0.3 /Au 25 (111) multilayers (the numbers indicate the thickness grown by evaporation in UHV has been investigated between 1.4 and 300 K. Byusing a stepped wedge-shaped middle Cu layer, eight different t values could be obtained in a single sample. The MR exhibits an oscillatory behaviour up to t = 3.4 nm with a period of 0.8–1 nm, which is consistent with the predictions of RKKY theory for oscillatory interlayer coupling across Cu(111).