Triple hysteresis loops were observed for amorphous ferrimagnetic Gd-Co films near the magnetic compensation temperature, which can be a consequence of both the spin-flop transition and the chemical composition gradient. In the work, an assessment of the possible chemical inhomogeneity of the films based on magnetic measurements was carried out and its relationship with the thickness of the samples was observed.

The influence of a number of physical factors on the structural and hysteresis properties of multilayer films (Cr-Mn)/Fe Ni has been studied. By indirect signs, the presence of antiferromagnetism in Cr-Mn layers with a Mn content in the range of 20-40 at.% has been established. It is shown that in such structures, the exchange bias effect can be observed, but only when the thickness of the antiferromagnetic layer is greater than 40 nm. The initial reason for the low "fixing" properties of the Cr-Mn layer is its weak magnetic anisotropy, which is superimposed with instability in the reproduction of the micro-structure. The use of substrate heating during film deposition increased the reproducibility of microstructure parameters and hysteresis characteristics but led to a weakening of the exchange bias effect, apparently due to changes in the structure and composition of the interlayer interface.

The article presents the results of a systematic study of the crystalline structure, microstructure, and hysteresis properties of (Cr80Mn20)/Fe bilayers, deposited on buffer coatings of various metals (Cr, Fe, W, Ta). It has been established that depending on the composition of the buffer coating and the thickness of the Cr-Mn layer, the latter develops body-centered cubic structure with either the (110) or (200) texture, or none. It is shown that the Cr-Mn layer is a source of increased coercivity in the adjacent Fe layer and when is in a certain structural state and has a relatively large thickness (100 nm) induces exchange bias in the Fe layer. The regularities obtained are interpreted in terms of the antiferromagnetic ordering of Cr-Mn and its relatively weak magnetic anisotropy

FeNi films in circular shape with 3 mm in diameter obtained by magnetron sputtering in the presence of a constant magnetic field of various configurations are studied. The presence of a field created by a permanent magnet with a diameter of 1.2 mm, the magnetization of which is oriented perpendicular to the plane of the substrate, leads to the formation of a vortex-like magnetic structure in the film, characterized by diffuse domain walls.

The peculiarities of induced magnetic anisotropy and magnetization reversal processes of single-layer and 10 to 200-nm-thick multilayer Fe20Ni80 films, which were prepared by oblique angle deposition, have been studied. In-plane uniaxial magnetic anisotropy has been found for all single-layer films. Upon deposition of multilayer films, the substrate holder was rotated by 90° before the deposition of each of the subsequent layers. The axis of the resulting magnetic anisotropy was found to make an angle of 45° with the magnetic anisotropy axes of individual layers. The magnetization reversal processes in the samples are considered taking into account both the coherent magnetic moment rotation and the nucleation of reverse magnetization domains and domain wall motion.

Magnetic and structural properties iron oxide micro- and nanoparticles and composites based on epoxy resin at different mass concentrations of particles are investigated (0, 5, 10, 30%). Commercial Alfa Aesar microparticles and nanoparticles obtained by electric explosion of wire with different dispersion parameters were compared. Magnetoimpedance detection of stray magnetic fields of the obtained composites in the form of cylinders using a strip multilayer film element [FeNi/Cu]5/Cu/[FeNi/Cu]5 was carried out. It is shown that it is possible to determine the position of filled magnetic composites at different mass concentrations of magnetic micro- or nanoparticles with different parameters of dispersion of the ensemble using magnetoimpedance detection. Ключевые с

This paper presents a detailed study of the hysteresis properties of film structures based on bilayers of the (Cr-Mn)/Fe type. The temperature dependences of several parameters of the hysteresis loops of the Fe layers are determined for films varying in the composition and thickness of the Cr-Mn layer, as well as in the structure of buffer coatings. The compositional and temperature intervals of the existence of the antiferromagnetic ordering in the Cr-Mn layer and the related features of the temperature changes in the coercive force, its anisotropy in the plane of the films and the exchange bias field are established. The causal analysis of the established regularities is performed.

Magnetic properties and peculiarities of the domain structure of multilayer [Ti/FeNi]х/Cu/[FeNi/Ti]x elements, the geometry of which ensures the high magnetoimpedance effect, are studied by varying the number of layers in the range x = 0–5. Peculiarities of the magnetization processes of the multilayer structures, which are magnetized at both substrate and free surfaces, are analyzed. It has been found that elements in which the magnetization reversal from the free side occurs by rotation of the magnetization vector have a higher magnetoimpedance effect compared to elements in which the magnetization reversal occurs with the formation of 180° domain walls both in the layer from the side of the substrate and the free layer as well.

Thermomagnetic processing of films of the finemet type with an easy magnetization axis in the plane under the action of a constant and rotating magnetic field was carried out in order to obtain an isotropic state. After heat treatment in a constant field, the easy magnetization axis was reoriented along the line of action of the field, as a result of which the domain walls were oriented along the new axis. After thermomagnetic treatment in a rotating field regions with different anisotropy patterns, including isotropic regions, were revealed.

In this work, the results of magneto-optical and magnetometric measurements carried out on YIG/FeNi film two-layer structures are presented. YIG films were grown by liquid phase epitaxy, and FeNi films were deposited using magnetron sputtering. It has been established that in the YIG/FeNi system the interlayer coupling is mainly due to the magnetostatic interaction.

Longitudinal giant magnetoimpedance effect of [Fe21Ni79/Cu]5/Cu/[Fe21Ni79/Cu]5 film element was investigated depends on stray magnetic field of epoxy magnetic composite with 30 % weight concentration of iron oxide magnetic microparticles. Configuration of an experiment was a model of thrombus detection in a blood vessel. Stray magnetic field was varied by movement of a magnetic composite above the element perpendicular to the long side. Composite was either magnetized or not to the state of remanence. As the magnetic composite approaches the GMI element, MI ratio curves are smoothed and shifted along the field axis and maximum value of the MI ratio decreases. Magnetic properties of magnetic composite and film element were investigated as well.

Планарные ансамбли многослойных периодических квадратных микроэлементов типа [Cu(6 nm)/FeNi(100 nm)]5 были получены методом ионно-плазменного распыления на стеклянные подложки с использованием сетчатых медных масок. Особенности поверхности микроэлементов анализировались с помощью стилусного профилометра, оптической и сканирующей электронной микроскопии. Статические магнитные свойства и особенности магнитной доменной структуры исследовались с использованием магнитооптического Керр-эффекта. Полученные планарные ансамбли могут использоваться как составная часть пленочных элементов детекторов слабых магнитных полей, работающих на основе магнитного импеданса (МИ), для повышения чувствительности МИ отклика к внешнему магнитному полю. Ключевые слова: многослойные пленочные структуры, ансамбли микроэлементов, периодические структуры, гигантский магнитоимпедансный эффект.

The results of the study of the magnetic properties of exchange coupled Tb–Co/FeNi film structures obtained by magnetron sputtering in a wide range of temperatures are presented. It is shown that a decrease in the Zeeman energy upon approaching the compensation temperature of the ferrimagnetic layer is accompanied by a change in the sequence of magnetization reversal of the layers. The efficiency of the interlayer exchange coupling weakly changes with temperature.

The structure and magnetic properties of thin polycrystalline Co100-xWx (030) films deposited by magnetron sputtering on glass substrates, including those containing buffer layers Ta, W and Ru, have been investigated. It was found that pure Co films are non-single-phase and contain hpc and fcc crystal modifications. Doping leads to an increase in the concentration of the fcc phase and enhance the texture (111), and subsequently to the amorphization of the films. Buffer layers had a certain influence on the depth and concentration localization of these transformations. A characteristic feature of the magnetism of Co-W films is a significant perpendicular component in the macroscopic magnetic anisotropy, which leads to a "trance critical" magnetic state. It was shown that its source was a textured fcc phase, the crystal anisotropy of which was enhanced by the doping of cobalt with tungsten.

A phenomenological model of the formation of exchange bias field and coercivity of polycrystalline ferromagnet/antiferromagnet composites is constructed by an example of the Fe19Ni81/Fe50Mn50 system. Based on the experimental data on temperature variations of the hysteresis properties, the estimation of distributions of crystallite blocking temperature and crystallite magnetic anisotropy constant for the antiferromagnetic layer is performed. The obtained results are used in order to perform the micromagnetic simulation of the temperature dependences of the coercivity and exchange bias field of ferromagnetic layer. It is shown that the micromagnetic model can be used successfully for the analysis and prediction of hysteresis properties of film with the exchange bias.

The magnetic properties of exchange-coupled Tb-Co/FeNi film structures obtained by magnetron sputtering were studied in a wide temperature range. It was shown that a decrease in the Zeeman energy when approaching the compensation temperature of the ferrimagnetic layer was accompanied by a change in the sequence of magnetization reversal of the layers. The efficiency of the interlayer exchange interaction varies with temperature very little.

The magnetic and magnetoresistive properties of layered film composites of the M/Fe20Ni80 type, where M = Fe86Al14, Fe40Co60, have been investigated. The effect of elastic deformation on the hysteresis and magnetoresistive properties of individual layers and bilayer films is determined. It is proposed to consider the synergy of magnetostriction and magnetoresistance of individual layers in a bilayered structure as a tensomagnetoresistive effect, which has the potential for practical application in force-sensing devices and for quantitative estimation of the magnetostrictive properties of materials in the film state.

The magnetic and magnetocaloric properties of amorphous ferrimagnetic Gd-Co films with perpendicular magnetic anisotropy were studied in a wide range of fields and temperatures. The change in the sign of the magnetocaloric effect near the compensation temperature occurs almost abruptly when the magnetic field is oriented perpendicular to the film plane. In a certain temperature range, it happens when the field is oriented along the plane of the sample. The most probable reason for the blurring of this transition is the appearance of a non-collinear magnetic structure.