Spin valves that comprise synthetic antiferromagnet as a component of pinned layer and an exchange-coupled ferromagnet/Ru/ferromagnet structure in the free layer have been prepared by magnetron sputtering. Microobjects have been formed from spin valves by optical and electron-beam lithography. It has been shown that the shift of the low-field magnetoresistance hysteresis loop decreases as the thicknes of the Ru spacer in the free layer of spin valve increases. The almost hysteresis-free odd-field dependences of the magnetoresistance were obtained for micron-sized samples; in this case, the sensitivity is 0.2%/Oe.

Magnetron sputtering was used to prepare spin valves with the Ta/Ni 80 Fe 20 /Co 90 Fe 10 /Cu/Co 90 Fe 10 /Ru/Co 90 Fe 10 /Fe 50 Mn 50 /Ta composition. Changes in the functional characteristics of the spin valves were studied in a temperature range of–180 to +160°C. The maximum temperature at which the functional characteristics of spin valve remain unchanged was shown to depend on the relationship of thicknesses of Co 90 Fe 10 layers separated by the Ru interlayer.

The effect of the chromium layer thickness on the magnetic state of an [Fe/Cr/Gd/Cr] n multilayer structure is studied. A series of Fe/Cr/Gd structures with Cr spacer thicknesses of 4–30 Å is studied by SQUID magnetometry and ferromagnetic resonance in the temperature range 4.2–300 K. The obtained experimental results are described in terms of an effective field model, which takes into account a biquadratic contribution to the interlayer coupling energy and a nonuniform magnetization distribution inside the gadolinium layer (which was detected earlier). Depending on the magnetic field and temperature, the following types of magnetic ordering are identified at various chromium layer thicknesses: ferromagnetic, antiferromagnetic, and canted ordering. A comparison of the experimental and calculated curves allowed us to determine the dependence of the bilinear (J 1) and biquadratic (J 2) exchange constants on chromium layer thickness t Cr. Weak oscillations at a period of about 18 Å are detected in the J 1(t Cr) dependence in the range 8–30 Å. The interlayer coupling oscillations in the system under study are assumed to be related to the RKKY exchange interaction mechanism via the conduction electrons of Cr.

The magnetic structure of Fe/Cr/Gd superlattices is investigated using complementary methods of SQUID magnetometry and polarized neutron reflectometry. The complex magnetic behavior of the given system is caused by exchange interaction between the 3d (Fe) and 4f (Gd) layers of the ferromagnetic metals through the Cr antiferromagnetic spacer layer. It is found that a nonuniform profile of magnetization forms within the Gd layers under the influence of this interlayer interaction.