The effect of non-magnetic cap-layers on the amplitudes and the phases of the oscillations of interlayer exchange coupling (IEC) is studied theoretically on ab initio level. We employ a spin-polarized surface Green function technique within the tight-binding linear muffin-tin orbital method and the Lloyd formulation of the IEC. Application is made to Co/Cu/Co(001) trilayers with Cu-cap layers interfacing vacuum through the dipole barrier.

We investigated the induced magnetic behaviour of the Ag of Fe/Ag multilayers with low temperature nuclear orientation. The experiments show induced magnetic moments in all samples. Furthermore, multilayers with 2ML and 4ML of Ag, these moments do not lie in the plane of the multilayer at low external magnetic fields.

Single crystalline spinel structure ferrite thin film bilayers exhibit nearly ideal exchange coupling at room temperature. In these bilayers, the blocking temperature is only limited by the Curie temperature of the (Mn,Zn)Fe2O4. Up to the Curie temperature of the soft (Mn,Zn)Fe2O4 layer, the magnetization loops indicate that exchange anisotropy dominates the magnetization of the soft layer up to magnetic fields on the order of the coercive field of the hard CoFe2O4layer.

The magnetic interlayer exchange coupling in Fe/Si-based thin film structures employing sputtered multilayers with variations of Si-alloyed Fe for the magnetic layers and Fe-alloyed Si spacers, as well as wedge-shaped MBE-grown Fe/Si/Fe sandwich samples has been systematically studied. From structural and magnetic analysis it is concluded that ultrathin Si and FexSi100-x (x < 50) spacer layers transform into a crystalline iron suicide with a composition close to Fe50Si50. The exchange coupling mediated by this metallic suicide is antiferromagnetic and depends on the spacer thickness in an exponential, i.e. non-oscillatory, manner with a universial characteristic decay length of 3–4 Å at room temperature. This observation can be qualitatively explained within the framework of a recent coupling theory on the premise that the FeSi interlayer has the metastable CsCl(B2)-structure.

The indirect exchange coupling in W(110)/Fe/Cr/Fe/Cr trilayers was determined by analysis of magnetization curves measured by Kerr magnetometry. We adjusted the uniaxial in-plane anisotropies in the two Fe layers in such a way that the easy axes were orthogonal, [001] in the 1st, [110] in the 2nd layer. This allows an independent determination of both bilinear (i) and biquadratic (J2) coupling constants. We determined tJ and J2 as a function of Cr interlayer thickness (tcT = 0 – 4 nm), preparation temperature of the interlayer Tcr=100 – 500 K, and as a function of temperature (T = 100 – 300 K). Results for the exchange coupling are correlated to the particular lateral thickness fluctuation of the Cr spacer.

We present the results of the transport and magnetization measurements of electrodeposited Co/Cu multilayers grown in a single electrolyte based on C0SO4, H3BO3 and CuSO4. The samples are deposited on glass substrate covered by a 500 Å thick Cu buffer layer. X-ray diffraction performed on the samples shows fee structure of both Co and Cu layers with preferential (111) orientation. Resistivity measurements show a giant magnetoresistance effect of about 4% at room temperature for multilayers with Co and Cu thickness between 4 nm ≤ tco ≤ 6 nm and 3 nm ≤ tcu ≤4 nm respectively. For Co thickness tCo ≤ 15 nm, the magnetoresistance completely vanishes indicating that there is no more continuous Co layer. The indirect antiferromagnetic exchange coupling between magnetic Co layers is relatively large for 4 nm thick Cu spacer layer and gives rise to a temperature dependence of about 30% between room temperature and 4.2 K.

There is considered the dependence of magnetic ordering type in multilayer structures on the magnitude of exchange interaction between magnetic layers and the interlayer surfaces roughness. With a simple example of the three-layered structure we found the areas of the existence of such states as: (i) domain structure, (ii) noncollinear ordering of homogeneous magnetic layers, (iii) collinear ferromagnetic phase, and (iiii) collinear antiferromagnetic phase.