ANTIFERROMAGNETIC EXCHANGE COUPLING AND MAGNETORESISTANCE OF FE/CR MULTILAYERS - INFLUENCE OF 3RD ELEMENTS IN CR LAYERS

We have investigated the influence of third elements (Ti, V, Mn, Nb, Mo and Ru) in Cr layers on the antiferromagnetic exchange coupling and the magnetoresistance (MR) of Fe/ Cr multilayers. The coupling strength shows a drastic decrease by the addition of Ti, V and Nb, which are situated on the left side of Cr in the periodic table. On the other hand, it does not change or increases by the addition of Mn, Mo and Ru, which are situated on the same series as or on the right side of Cr. This fact suggests that the coupling strength depends strongly on whether the Fermi level of the interlayer (Cr) increases or decreases. We have found that the magnitude of MR does not always correlate with the coupling strength, but mainly with the remnant magnetization ratio, M(r)/M(s).