•Exchange bias in antiferromagnetic/ferrimagnetic layered system.•Magnetic compensation state for ferrimagnetic Gd-Co layer.•Sharp increase and inversion of the sign of exchange bias field for Gd-Co ...layer.
The exchange bias effect in FeNi/FeMn/GdxCo100-x films with a pinning antiferromagnetic FeMn layer and an exchange-biased ferrimagnetic amorphous Gd-Co layer was studied. The FeNi layer allows the formation of the fcc lattice of FeMn, i.e. the antiferromagnetic γ-phase of FeMn. The Gd content was varied within 15–25 at. % in order to obtain different temperature dependences of the spontaneous magnetization Ms(T) of the Gd-Co layer. The magnetic properties of the films were determined from hysteresis loops measured in the temperature range 5–350 K. A correlation between Ms(T) and the temperature dependences of the exchange bias field HebGdCo(T) was established. In particular, it was shown that there is an inversion of the sign and sharp increase of the value of HebGdCo near the magnetic compensation state. The first one is a consequence of the minimization of the spontaneous magnetization of Gd-Co layer at the compensation temperature. The second one shows the predominance of the exchange interaction of the antiferromagnetic layer with the cobalt magnetic sub-system of the ferrimagnetic layer as a contribution to the interlayer exchange coupling.
The cross section of the process e + e − → π + π − has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The ...measurement is based on an integrated luminosity of about 88 pb − 1 , of which 62 pb − 1 represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed. Published by the American Physical Society 2024
Multilayer films Fe
20
Ni
80
/FeMn/FM (with FM = Ni, Fe
11
Ni
89
, Fe
20
Ni
80
, Co
30
Ni
70
, Fe, Co) have been prepared and their structure has been estimated. Their hysteretic properties and ...interlayer coupling parameters have been studied in a temperature range of 5–350 K. Regularities of the magnetization reversal of ferromagnetic layers under magnetic exchange-bias conditions have been interpreted.
In this paper we studied the possibility of tailoring the functional properties of the multilayer magnetoresistive medium with unidirectional anisotropy and the anisotropic magnetoresistance effect ...(AMR). Objects of the research were composite Co-Al2O3 films and Ta Fe20Ni80 Fe50Mn50 Fe20Ni80 Co-Al2O3 Fe20Ni80 Ta multilayers structures obtained by magnetron sputtering and selectively subjected vacuum annealing. Structure, magnetic and magnetoresistive properties of the films in the temperature range 77÷440 K were investigated.
The cross section of the process e + e − → π + π − has been measured in the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The ...measurement is based on a full dataset collected below 1 GeV during three data taking seasons, corresponding to an integrated luminosity of about 62 pb − 1 . In the dominant ρ -resonance region, a systematic uncertainty of 0.7% has been reached. At energies around ϕ -resonance the π + π − production cross section was measured for the first time with high beam energy resolution. The forward-backward charge asymmetry in the π + π − production has also been measured. It shows a strong deviation from the theoretical prediction based on the conventional scalar quantum electrodynamics framework, and it is in good agreement with the generalized vector-meson-dominance and dispersive-based predictions. The impact of the presented results on the evaluation of the hadronic contribution to the anomalous magnetic moment of muon is discussed. Published by the American Physical Society 2024
•Depth of the interlayer diffusion in FeMn/FeNi films at Ta=400 °C is at least 5 nm.•Depth of mn diffusion depends on the composition of ferromagnet layers.•As a result of annealing, Mn migrates most ...actively into FeMn/Co film.•After annealing at 400 °C the exchange bias in the FeMn/Co film disappears.
In this work a comparative systematic study of the crystal structure and magnetic properties of Fe50Mn50/(Fe, Co, Ni, Fe20Ni80, Fe11Ni89, Co30Ni70) films in as-deposited state and after subsequent vacuum thermomagnetic treatment at temperatures up to 400 °C was performed. Thermally induced changes in magnetic properties are described quantitatively and critical role of the interlayer diffusion leading to partial or complete (for Co layer) destruction of the antiferromagnetic layer is demonstrated. The result of such compositional changes is a significant decrease or disappearance of exchange bias.
The phenomenon of spontaneous spin reorientation in Gd–Сo amorphous films, which results from the competition between the perpendicular magnetic anisotropy and shape anisotropy, is studied. It is ...shown that the reorientation occurs via the formation of a fine-grained nonuniform magnetic structure called hypercritical state in a wide temperature range. Magnetic domains in the spin-reorientation region are characterized using magnetic and magneto-optical measurements. Based on the experimental magnetometric data and results of simulating the temperature dependences of spontaneous magnetization, the phase diagram of the films containing 16–26 at % Gd is constructed, which, being plotted on coordinates elemental composition—temperature, exhibits the ranges of existence of the perpendicular anisotropy, transition magnetic anisotropy (hypercritical state), and planar magnetization state.
FeNi/FeMn/GdxCo100-x multilayered films were prepared by magnetron sputtering. The Gd–Co layer had different temperature dependences of the spontaneous magnetization due to the different Gd content. ...The magnetic properties of the films were determined from hysteresis loops measured in the temperature range 5–473 K. In order to determine the existence of a long-range interaction and a mutual influence of two exchange bias systems through the formation of bulk continuous magnetic structure in the antiferromagnetic layer special cooling procedure with FeNi and Gd–Co magnetizations saturated in a direction parallel or antiparallel to each other was used. The observed difference in the exchange bias between the two cooling configurations was discussed.
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•Antiferromagnetic/ferrimagnetic layered system with exchange bias.•Cooling at parallel or antiparallel FeNi and Gd–Co magnetizations.•Stepwise change of the FeMn/Gd–Co interfacial exchange coupling energy near Tcomp.
The structure and magnetic properties of thin polycrystalline films of Co
100 –
x
W
x
(0 ≤
x
≤ 30) deposited by magnetron sputtering on glass substrates are investigated including those containing ...buffer layers of Ta, W, and Ru. It is found that films of pure Co are non-single-phase and contain hcp and fcc crystalline modifications. Doping leads to an increase in the concentration of the fcc phase and an enhancement of the texture of the (111) type, and subsequently to the amorphization of the films. The buffer layers influence to a certain extent 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 “supercritical” magnetic state. It is shown that its source is the textured fcc phase, the crystalline anisotropy of which is enhanced as a result of doping of cobalt with tungsten.
In tests on 10 healthy men, we recorded EMGs related to the performance of simple (with one degree of freedom) linear movements of the right hand; straight movement trajectories lay within the ...parafrontal planes, and principal component analysis (PCA) was used for the evaluation of complexity of the central control of such movements. The first principal component was discriminated from EMG activity of eight muscles involved in the movements, and the magnitude of this component was associated with complexity of the central control of the performed movement. As was believed, the control of the task performance by the CNS was more complex when the size of the first principal component was smaller. It was found that the complexity of the central control was significantly smaller for the movements performed within a proximal operational zone and gradually increased for more distal trajectories. With respect to the central control, the movements provided by cyclic contraction and elongation of the extensor muscles were simpler. Hysteresis of the muscle contractions exerted ambiguous effects on the complexity of the control. It is known from skeletal and muscular anatomy that even mechanically simple movements may have different complexities at the level of the musculoskeletal system, which is taken into account by the central nervous system when performing these movements. This raises the problem of creating methods for assessing the complexity with which the CNS collides with the realization of motor tasks.
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