Publications by authors named "Perov N"

The search for novel materials with enhanced characteristics for the advancement of flexible electronic devices and energy harvesting devices is currently a significant concern. Multiferroics are a prominent example of energy conversion materials. The magnetoelectric conversion in a flexible composite based on a piezopolymer layer and a magnetic elastomer layer was investigated.

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The controllable delivery of drugs is a key task of pharmacology. For this purpose, a series of polymer composites was synthesized via the cross-linking of hyaluronate and a hyaluronate/polyacrylate mixture with FeO nanoparticles. The cross-linking imparts magnetic properties to the composites, which are more pronounced for the ternary hyaluronate/polyacrylate/γ-FeO composites compared with the binary hyaluronate/FeO composites.

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In this work, an attempt was made to reveal and explain the influence of the process of formation of 2D nanostructures at the surface of an amorphous alloy (an alloy with the composition Co75Si15Fe5Cr4.5Al0.5 (in at.

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The polycrystalline SrFeO samples deeply substituted up to at.67% by Al, Ga, In, Co, and Cr cations with a high configurational mixing entropy were prepared by solid-phase synthesis. Phase purity and unit cell parameters were obtained from XRD and analyzed versus the average ionic radius of the iron sublattice.

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Multilayered magnetoelectric materials are of great interest for investigations due to their unique tuneable properties and giant values of magnetoelectric effect. The flexible layered structures consisting of soft components can reveal lower values of the resonant frequency for the dynamic magnetoelectric effect appearing in bending deformation mode. The double-layered structure based on the piezoelectric polymer polyvinylidene fluoride and a magnetoactive elastomer (MAE) with carbonyl iron particles in a cantilever configuration was investigated in this work.

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Iron-containing oxides are the most important functional substance class and find a tremendous variety of applications. An attractive modern application is their use in biomedical technologies as components in systems for imaging, drug delivery, magnetically mediated hyperthermia, etc. In this paper, we report the results of the experimental investigation of submicron YFeO garnet particles obtained in different sizes by solution combustion synthesis (SCS) using glycine organic fuel to discuss the interdependence of peculiarities of the crystal and magnetic structure and size's influence on its functional magnetothermal performance.

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The kinetics of hydrogen reduction of magnetite was investigated in different magnetic fields. The magnetic moment measurements were used for the control of the reaction. A strong difference in the magnetic properties of the reaction results was obtained for applied strong and weak magnetic fields.

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Multiferroics are materials that electrically polarize when subjected to a magnetic field and magnetize under the action of an electric field. In composites, the multiferroic effect is achieved by mixing of ferromagnetic (FM) and ferroelectric (FE) particles. The FM particles are prone to magnetostriction (field-induced deformation), whereas the FE particles display piezoelectricity (electrically polarize under mechanical stress).

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Magnetic oxides are promising materials for alternative health diagnoses and treatments. The aim of this work is to understand the dependence of the heating power with the nanoparticle (NP) mean size, for the manganite composition LaSrMnO (LSMO)-the one with maximum critical temperature for the whole La/Sr ratio of the series. We have prepared four different samples, each one annealed at different temperatures, in order to produce different mean NP sizes, ranging from 26 nm up to 106 nm.

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The tunable magnetic properties of amorphous ferromagnetic glass-coated microwires make them suitable for a wide range of applications. Accurate knowledge of the micromagnetic structure is highly desirable since it affects almost all magnetic properties. To select an appropriate wire-sample for a specific application, a deeper understanding of the magnetization reversal process is required, because it determines the measurable response (such as induced voltage waveform and its spectrum).

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Article Synopsis
  • A study on bulk TmFeO3 was conducted using electron paramagnetic resonance (EPR) to explore how temperature affects spin behavior and interaction mechanisms.
  • The research revealed an antiferromagnetic transition at 85 K, accompanied by a ferromagnetic state due to changes in spin orientation, and identified different magnetic phases at higher temperatures (above 90 K).
  • The findings also indicated that spin interactions among different ions lead to varied magnetic phases above and below 85 K, and that EPR techniques can effectively reveal strong spin coupling in antiferromagnetic materials.
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The description of the magnetic properties of amorphous alloys and comparison of the model evaluation with experimental data have been carried out in terms of the magnetic theory of disordered systems (Biryukov's theory). The hysteresis loops for a number of amorphous metallic glasses have been investigated and it also has been shown that Biryukov's hypothesis about the weak correlation between spin and electrostatic components is true for the amorphous magnetic system that permits to interpret collectively the results of different magnetometric experiments.

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We present the results of numerical simulation of magnetodielectric effect (MDE) in magnetorheological elastomers (MRE)-the change of effective permittivity of elastomer placed under the external magnetic field. The computer model of effect is based on an assumption about the displacement of magnetic particles inside the elastic matrix under the external magnetic field and the formation of chain-like structures. Such displacement of metallic particles between the planes of capacitor leads to the change of capacity, which can be considered as a change of effective permittivity of elastomer caused by magnetic field (magnetodielectric effect).

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Barium hexaferrite powder samples with grains in the μm-range were obtained from solid-state sintering, and crystals with sizes up to 5 mm grown from PbO, Na₂CO₃, and BaB₂O₄ fluxes, respectively. Carbonate and borate fluxes provide the largest and structurally best crystals at significantly lower growth temperatures of 1533 K compared to flux-free synthesis (1623 K). The maximum synthesis temperature can be further reduced by the application of PbO-containing fluxes (down to 1223 K upon use of 80 at % PbO), however, Pb-substituted crystals BaPbFeO with Pb contents in the range of 0.

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The results of a detailed study of magnetic properties and of the microstructure of SiMn films with a small deviation from stoichiometry are presented. The aim was to reveal the origin of the high temperature ferromagnetic ordering in such compounds. Unlike SiMn single crystals with the Curie temperature ~30 K, considered Si Mn compounds with x  =  0.

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We present recent experimental results on the structural, electrical, magnetic, and magneto-optical properties of Mn-implanted Si and Co-doped TiO(2-delta) magnetic oxides. Si wafers, both n- and p-type, with high and low resistivity, were used as the starting materials for implantation with Mn ions at the fluencies up to 5 x 10(16) cm(-2). The saturation magnetization was found to show the lack of any regular dependence on the Si conductivity type, type of impurity and the short post-implantation annealing.

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The magnetic, magnetotransport, and magnetocaloric properties near compound phase transitions in Ni50Mn35In14Z (Z = In, Ge, Al), and Ni48Co2Mn35In15 Heusler alloys have been studied using VSM and SQUID magnetometers (at magnetic fields (H) up to 5 T), four-probe method (at H = 0.005-1.5 T), and an adiabatic magnetocalorimeter (for H changes up to deltaH = 1.

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A series of new 1,3,4-thiadiazine derivatives have been synthesized and their effect on the human platelet aggregation in vitro has been studied. All the tested substances inhibit the human platelet aggregation induced by ADP and arachidonic acid in a broad concentration range. The most active 1,3,4-thiadiazines (L-19, L-28 and L-31) effectively inhibit platelet aggregation at concentrations within 0.

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The magnetoimpedance (MI) effect in Fe73.5Si13.5B9Nb3Cu1 melt-spun amorphous ribbons has been studied in the frequency range (1-500 MHz).

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Article Synopsis
  • Ferroelastic composites are advanced materials that exhibit significant changes in their mechanical properties when subjected to magnetic fields.
  • The study shows that these effects are primarily due to the movement of magnetic particles within a polymer matrix, which is influenced by the applied magnetic field.
  • The text also introduces a model that explains how the arrangement of these particles is affected by the external magnetic influence, enhancing our understanding of magnetoactive elastomers.
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It has been shown for the first time that the outer mitochondrial membrane has a low permeability for ADP and can control its diffusion into cells in vivo. Respiration of saponin-skinned cardiac and skeletal muscle fibers is maximally stimulated by millimolar concentrations of external ADP. The apparent Km values for ADP are equal to 297 +/- 35 and 334 +/- 54 microM, respectively.

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Possible reasons for retarded intracellular diffusion of ADP were investigated. The isolated skinned cardiac fibers were used to study apparent kinetic parameters for externally added ADP in control of mitochondrial respiration. Participation of myosin-ATPase in binding of ADP within cells as it was supposed earlier (Saks, V.

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Effect of drugs, which are able to elevate the intracellular level of cAMP, on resistance of human umbilical vein endothelial cells (HUVEC) to cholestane-3 beta,5 alpha, 6 beta-triol (Triol)-induced injury was studied. Triol at a concentration of 62 microM caused death of 50% of cells after a 24 hour incubation. Addition of forskolin (10 microM), methylisobutylxantine (100 microM), or 8-Br-cAMP (100 microM) into the incubation medium prevented injury of HUVEC under these conditions.

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The fine structure of the centriolar system was studied on serial sections of 90 endothelial cells of human aorta (50 to 60 years) in regions without atherosclerotic platelets and with fibrous and atheromatous platelets and of 30 endothelial cells of human embryonic aorta (22-24 weeks). The vast majority (95%) of endothelial cells of the atheromatous platelets were shown to have a primary cilium over 1 micron long which gives on the basal surface in all the cells. In the regions without platelets and with fibrous platelets a cilium was observed in about 20% of cells and it gives in the vessel lumen.

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Ultrastructural organization of centriolar complexes in 90 adult human aortic endothelial cells from uninvolved areas, fibrous and atheromatous plaques and 30 endothelial cells from human embryonic aorta were studied using serial sections. Primary cilia protruding from the abluminal cell surface were found on 28 of 30 endothelial cells from atheromatous plaques. Only five of 30 cells from either fibrous plaques or uninvolved areas developed primary cilia protruding to the lumen.

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