For microobjects based on spin valves, changes in the magnetic state are observed under the action of short-term direct current. It has been shown that the magnetic moment of the free layer rotates when a certain current density is attained. The rotation angle grows with increasing current density. The magnetic moment rotates predominantly due to the thermal effect of current. Rotation angle changes caused by spin accumulation in Ta or NiFeCr layers and the transfer of the spin-orbit torque of electrons to the magnetic moment of the free layer have been revealed.

Spin valves with a CoFe/Dy/CoFe composition in the lower part of their structure have been manufactured by magnetron sputtering. The effect of prolonged storage and temperature on the structure and magnetotransport properties of spin valves has been studied. The change in the compensation temperature was used as an indicator of the intensity of diffusion processes in the exchange-coupled CoFe/Dy/CoFe structure. It has been revealed that diffusion induced changes in the magnetotransport properties become smaller with a decrease in the dysprosium layer thickness. It has been shown that the nanostructure still contains pure dysprosium, the atoms of which do not participate in the sperimagnetic ordering of the Dy–Co–Fe interface, even at a small nominal thickness (4 nm) of the dysprosium layer 3 months after sputtering.

Flexible spin valves were prepared by magnetron sputtering on polyimide substrates. The buffer layer that reduces significantly the effect of the polymer substrate on the spin valve microstructure and magnetoresistive properties was revealed. Bending deformation was applied to the microobjects based on the flexible spin valves in parallel to anisotropy axes. It was revealed that during the bend the magnetoresistance changes due to the joint impact of both the change of the magnetic field projection on the film plane and the change of the magnetic properties of the ferromagnetic layers. The obtained dependences have been used in construction of bending sensor, in which the flexible spin valve microstripes were united into the Wheatstone bridge.

Dysprosium nanolayers differing in the thickness are prepared by magnetron sputtering on Al2O3(R) substrates using Co90Fe10, β-Ta, and Nb buffer layers. The correlation between the crystallographic texture type and peculiarities of temperature dependences of electrical resistance of polycrystalline dysprosium films is studied. It is found that, in the case of deposition of Dy directly on Al2O3(R), a two-component texture forms in the rare-earth metal layer. One of the components is characterized by the hexagonal axis parallel to the film plane, whereas the other component is characterized by the axis perpendicular to the film plane. In the case of deposition of Dy on the β-Ta buffer layer, the microstructures of Al2O3 and Dy are shown to demonstrate the matching through β-Ta, and the perfection of the two-component texture increases. In the antiferromagnetic state, the texture components become “phases” differing in the orientation of magnetic helicoid axis, and the anitiferromagnetic ordering occurs at different temperatures.

Rhombus-shaped microobjects formed by strips of two micrometers wide were fabricated from the spin valve film. The influence of the shape anisotropy on the layers magnetic moment rotation during the spin valve magnetic reversal is studied. A method for two-stage thermomagnetic treatment in a direction-fixed magnetic field has been found. The method allows to obtain the opposite sign values of the exchange bias fields in the non-parallel rhombus sides. The direction of the formed exchange bias is determined by the deviation of the strip from the uniaxial anisotropy axis and from the magnetic field applied during thermomagnetic treatment. Based on a rhombus-shaped microobject made from a single spin valve film, the device is a Full Wheatstone bridge. Each side of the rhombus is an active magnetically sensitive element.

The Ta/Dy/Ta nanostructures are fabricated by high-vacuum magnetron sputtering. Resistance and longitudinal magnetoresistance are measured. It is shown that the observed the effect of magnetic field on resistance are due to the competition of two effects of different nature. The negative isotropic magnetoresistance in the dysprosium layer is due to the alignment of local magnetic moments in the direction of the applied magnetic field. The positive longitudinal magnetoresistance in tantalum layers is caused by a change in the conditions of scattering of electrons during the accumulation of electrons with opposite spins on opposite surfaces of the metal film with strong spin-orbit coupling.

Spin valves containing a Dy layer have been formed on an elastic polyimide film by magnetron sputtering. The field dependences of the magnetoresistance of samples subjected to different tensile deformations have been measured. The character of the variations of the magnetoresistive properties of a spin valve subjected to tensile deformation is shown to depend on the thickness of the dysprosium layer. In particular, the thickness of the dysprosium layer affects the maximum relative elongation at which the magnetoresistance of spin valves remains unchanged.

Spin valves containing a Dy layer have been formed on an elastic polyimide film by magnetron sputtering. The field dependences of the magnetoresistance of samples subjected to different tensile deformations have been measured. The character of the variations of the magnetoresistive properties of a spin valvesubjected to tensile deformation is shown to depend on the thickness of the dysprosium layer. In particular, the thickness of the dysprosium layer affects the maximum relative elongation at which the magnetoresistanceof spin valves remains unchanged.

The effect of inert gas ions with different atomic masses (Ar + , Xe + ) on the magnetoresistance of Co 90 Fe 10 /Cu superlattices deposited on a silicon substrate has been investigated by comparison. The Ar + ion irradiation has been found to decrease the magnetoresistance more significantly than Xe + ion irradiation, which seems to be due to a larger average projective range for Ar + (R p = 5–6 nm) than that for Xe + (R p = 3.3–4.3 nm) and, accordingly, a greater depth of the atom mixing zone (∽(2–3)×R p ) when ions move from the top layers of the superlattice toward the substrate.

Exchange-biased nanostructures of the “spin valve” type, which include an additional layer of the rare-earth metal dysprosium, are made by magnetron sputtering. Temperature variations in the magnetotransport properties of the spin valves are used as an indicator of change in the magnetic state of the dysprosium nanolayer. Information on the formation of unidirectional magnetic anisotropy at the CoFe/Dy interface upon the transition through Néel temperature of dysprosium is obtained. It is shown that the antiferromagnetic phase in the polycrystalline dysprosium layer has noncollinear magnetic ordering. The temperature dependence of the angle between the directions of the magnetic moments at the dysprosium-layer boundaries is determined. The change in this angle observed in the entire temperature region of the existence of helicoidal ordering in dysprosium reflects the change in the period of the magnetic helicoid in dysprosium with temperature. Thus, a new method for studying chiral magnetics is proposed, in which the indicator of the helicoidal magnetic state is a spin valve possessing giant magnetoresistance, containing a layer of the helimagnet under investigation.

Dysprosium-based bottom spin valves with the thickness of the dysprosium layer comparable to the spatial period of the magnetic helicoid were fabricated by magnetron sputtering. Perfect fiber crystal texture was obtained in Dy layer sputtered on Ta underlayer. The inversion of magnetoresistive curves with temperature decreasing is observed. The explanation of these features is based on the paramagnet-antiferromagnet transition in dysprosium nanolayer and on the deformation of helicoidal magnetic structure by an applied magnetic field. It has been determined that at the same temperature and field the smaller is the thickness of the ultra-thin dysprosium layer, the greater is its magnetic moment. The Neel temperature was estimated for dysprosium nanolayer in Ta/Dy/Ta structures where the smallest thickness of the dysprosium layer was 10 nm. It has been revealed that the temperature of transition from paramagnetic to antiferromagnetic state is different in the film regions in which helicoid axis is close to parallel or perpendicular to the film plane.

Exchange-coupled spin valves based on ferromagnetic alloys CoFeNi and antiferromagnetic alloy FeMn are obtained on flexible polyimide substrates by magnetron sputtering. The magnetoresistive properties of films and microstrips of spin valves are measured at various degrees of bending deformation of the sample. The behavior of the dependence of the deformation sensitivity of the spin valve on the interaction between the magnetic layers and on the arrangement of the anisotropy axes with respect to the deformation vector is characterized. It is found that the deformation sensitivity decreases with an increase in the interval between the fields of magnetization reversal of the free and fixed layers in the spin valve.

The dependence of the Neel temperature on the thickness of the dysprosium layer has been studied. It is shown that the temperature range within which the paramagnetic–antiferromagnetic phase transition takes place depends on the microstructure and thickness of the dysprosium layer. Spin valves based on a CoFe alloy with dysprosium as an antiferromagnetic layer are manufactured via magnetron sputtering. It is shown that unidirectional anisotropy forms in the CoFe/Dy interface. The direction of the exchange bias field depends on the direction of the magnetic moment of the CoFe layer in the formation of exchange coupling.

Spin valves with holmium layers and three-layer structures metal/Ho/metal were prepared by magnetron sputtering. A holmium layer in the spin valves is polycrystalline with weak axial <002> texture. The structural coherence length along the hexagonal c-axis is approximately 2/5 of the total thickness of the holmium layer. Field dependences of the spin valves magnetoresistance were measured at different temperatures. Correlation was revealed between magnetic state in holmium layer and the shape of magnetoresistive curve. Deviation of magnetic moments of the reference layer and the adjacent part of holmium from the applied magnetic field was investigated. The field induced mobility of the magnetic helicoid in holmium layers was revealed.

A method of universal thermomagnetic treatment forming a pairwise opposite exchange bias in spin valves, which are sensor elements of a Wheatstone bridge, has been developed. The method is based on the formation of two magnetic phases in a spin valve upon the transition of a synthetic antiferromagnet into a spin-flop state. Thermomagnetic treatment in a two-phase state leads to the formation of a pairwise mutually opposite exchange bias in different elements of a Wheatstone bridge. The direction of a formed exchange bias is governed by the uniaxial anisotropy of every element.