LAYERED MAGNETIC-STRUCTURES - ANTIFERROMAGNETIC TYPE INTERLAYER COUPLING AND MAGNETORESISTANCE DUE TO ANTIPARALLEL ALIGNMENT

Layered Fe/Cr structures are known to display antiferromagnetic type interlayer coupling and a new magnetoresistance (MR) effect due to antiparallel magnetization alignment. We review our results and compare with data obtained by other groups. The strength of the coupling is found to be similar in multilayered structures and double layers. We consider briefly the possibility of dipolar coupling but come to the conclusion that it can be neglected. Concerning the new MR effect we will review the results of an experimental and theoretical study where the dependence of the effect on temperature and number and thickness of the magnetic layers in the layered structure was investigated. The basic assumption used in the theory was a spin dependent scattering of the electrons at the Fe-Cr interfaces. We have extended the investigations to Fe/V, Fe/Mn, Fe/Cu, Co/Au, Co/Cr and Co/Cu structures where the antiparallel alignment of the ferromagnetic layers is obtained via hysteresis effects. We find also an MR effect due to antiparallel alignment which is strong for Co/Au and Co/Cu but weak in the other cases. The experimental results and their possible interrelations will be discussed.