Glass-coated microwires exhibiting magnetic bistability have garnered significant attention as promising wireless sensing elements, primarily due to their rapid magnetization switching capabilities. These microwires consist of a metallic core with diameter , encased in a glass coating, with a total diameter . In this study, we investigated how the dimensions of both components and their ratio (/) influence the magnetization reversal behavior of Fe-based microwires.
View Article and Find Full Text PDFThe study encompasses an investigation of optical, photothermal and biocompatibility properties of a composite consisting of golden cores surrounded by superparamagnetic CoFeO nanoparticles. Accompanied with the experiment, the computational modeling reveals that each adjusted magnetic nanoparticle redshifts the plasmon resonance frequency in gold and nonlinearly increases the extinction cross-section at ~800 nm. The concentration dependent photothermal study demonstrates a temperature increase of 8.
View Article and Find Full Text PDFThe importance of magnetic micro- and nanoparticles for applications in biomedical technology is widely recognised. Many of these applications, including tissue engineering, cell sorting, biosensors, drug delivery, and lab-on-chip devices, require remote manipulation of magnetic objects. High-gradient magnetic fields generated by micromagnets in the range of 10-10 T/m are sufficient for magnetic forces to overcome other forces caused by viscosity, gravity, and thermal fluctuations.
View Article and Find Full Text PDFMagnetoimpedance (MI) in Co-based microwires with an amorphous and partially crystalline state was investigated at elevated frequencies (up to several GHz), with particular attention paid to the influence of tensile stress on the MI behavior, which is called stress-MI. Two mechanisms of MI sensitivity related to the DC magnetization re-orientation and AC permeability dispersion were discussed. Remarkable sensitivity of impedance changes with respect to applied tensile stress at GHz frequencies was obtained in partially crystalline wires subjected to current annealing.
View Article and Find Full Text PDFMagnetic nanocomposites based on hydroxyapatite were prepared by a one-step process using the hydrothermal coprecipitation method to sinter iron oxides (FeO and γ-FeO). The possibility of expanding the proposed technique for the synthesis of magnetic composite with embedded biologically active substance (BAS) of the 2-arylaminopyrimidine group was shown. The composition, morphology, structural features, and magnetic characteristics of the nanocomposites synthesized with and without BAS were studied.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2021
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).
View Article and Find Full Text PDFThe Middle East Respiratory Syndrome (MERS) is an acute inflammatory disease of the respiratory system caused by the MERS-CoV coronavirus. The mortality rate for MERS is about 34.5%.
View Article and Find Full Text PDFThe modern development of nanotechnology requires the discovery of simple approaches that ensure the controlled formation of functional nanostructures with a predetermined morphology. One of the simplest approaches is the self-assembly of nanostructures. The widespread implementation of self-assembly is limited by the complexity of controlled processes in a large volume where, due to the temperature, ion concentration, and other thermodynamics factors, local changes in diffusion-limited processes may occur, leading to unexpected nanostructure growth.
View Article and Find Full Text PDFWe propose a method for achieving THz ultra-broadband coherent absorption using the anti-reflection theory of metamaterials. The metamaterial absorber consists of a periodic array of electric ring resonators with a multilayered structure which form the desired refractive index dispersion and provide continuous anti-reflection over a wide frequency range. The destructive interference mechanism and resonance absorption of the absorber are determined by simulation analysis and numerical simulation.
View Article and Find Full Text PDFThe development of magnetic field sensors for biomedical applications primarily focuses on equivalent magnetic noise reduction or overall design improvement in order to make them smaller and cheaper while keeping the required values of a limit of detection. One of the cutting-edge topics today is the use of magnetic field sensors for applications such as magnetocardiography, magnetotomography, magnetomyography, magnetoneurography, or their application in point-of-care devices. This introductory review focuses on modern magnetic field sensors suitable for biomedicine applications from a physical point of view and provides an overview of recent studies in this field.
View Article and Find Full Text PDFThe magnetoelectric (ME) response in a trilayer structure consisting of magnetostrictive FeBSi amorphous microwires between two piezoelectric PZT (PbZrTiO) layers was investigated. Soft magnetic properties of wires make it possible to operate under weak bias magnetic fields below 400 A/m. Enhanced ME voltage coefficients were found when the microwires were excited by ac magnetic field of a frequency of 50-60 kHz, which corresponded to the frequency of electromechanical resonance.
View Article and Find Full Text PDFHere, we demonstrate the impact of ferromagnetic layer coating on controlling the magneto-optical response. We found that the transverse magneto-optical Kerr effect (TMOKE) signal and TMOKE hysteresis loops of NiFe thin layers coated with a Cr layer show a strong dependence on the thickness of the Cr layer and the incidence angle of the light. The transmission and reflection spectra were measured over a range of incidence angles and with different wavelengths so as to determine the layers' optical parameters and to explain the TMOKE behavior.
View Article and Find Full Text PDFAmorphous ferromagnetic materials in the form of microwires are of interest for the development of various sensors. This paper analyzes and argues for the use of microwires of two basic compositions of CoFeBSiCr and FeCoBSiCrMo as stress/strain and temperature sensors, respectively. The following properties make them suitable for innovative applications: miniature dimensions, small coercivity, low anisotropy and magnetostriction, tunable magnetic structure, magnetic anisotropy, and Curie temperature by annealing.
View Article and Find Full Text PDFThe microwave properties of composites containing Fe-based ferromagnetic microwires and carbon fibres have been investigated as part of a campaign to bring added functionalities into structural composites. A transmission window observed in 1-6 GHz demonstrates double-negative (DNG), , metamaterial characteristics in the composites containing short-cut carbon fibres and a parallel array of microwires; the metamaterial characteristic is due to the ferromagnetic resonance and a plasmonic behaviour, as short carbon fibres are proved to ameliorate DNG properties through enhancing the impedance of the composites. In parallel, magnetically tunable metamaterial features are realised in composites containing continuous carbon fibres and microwires, which can be switched on/off via rotating the electrical excitation direction.
View Article and Find Full Text PDFBaFeGaO (x ≤ 1.2) hexaferrites were synthesized via the usual ceramic technology. It has been established that with an increase in x, the unit cell and magnetic parameters monotonically decrease.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
September 2012
We indicate that the Magneto-Impedance sensor using amorphous wires has reached a new stage to view "Super MI sensor technology" based on three main advantageous factors of (i) micro sized head and micro power consumption chip, (ii) ultra-high sensitivity micro magnetic sensor with 1 pico-Tesla resolution at the room temperature without any electromagnetic shielding, and (iii) ultra-quick response magnetic sensor with GHz operation. We summarize systematically the magneto-impedance technology with the basic principle and mechanisms of three advantageous features for constitution of various high performance new sensor devices such as the electronic compass chip for mobile phones and smart phones and portable sensors for the magneto-encephalography, the magneto-spinography, and various bio-cell magnetic measurements. Possibility of new application to MI antenna in magnetic telecommunications is also discussed.
View Article and Find Full Text PDFFree radical homeostasis parameters of rat's brain mitochondria under conditions of sodium nitrite administration at the peak of hypoxia had been studied. Prior to study experimental animals have been divided into two groups depending on resistance to hypobaric hypoxia. In brain mitochondria of high-resistant to hypoxia rats increase of the nitrites-ions contents and also intensification of pro- and antioxidative processes were registered in comparison with the control group.
View Article and Find Full Text PDFThe morphogenetic process, the transition from the micelial to fungal growth phase in imperfect microscopic dimorphic fungi Phaeococcomyces de Hoog (strain Ch49), induced by high concentrations of transition metal ions, was considered in terms of the phase transition theory. It was shown that, although microscopic dimorphic fungi developing in the culture represent a system far from equilibrial, the transitions from the micelial to fungal phase under determined external influences have features characteristic for a common phase transition.
View Article and Find Full Text PDFThe peculiarities of the formation of colonies of dimorphous epilithic fungus Phaeococcomyces de Hoog isolated from marble were studied. The data obtained can be used for modeling the formation of colonies of dimorphous microscopic fungi.
View Article and Find Full Text PDFMathematical model of the development of the pattern of colonies is considered. The model represents the systems of differential equations of the first order. It includes non-dimensional parameters characterizing the following features: concentration of substrate, concentration of metabolic products--growth inhibitor, mycelium and spores, radial and specific rate of mycelium growth, rate of substrate consumption and production of metabolic products, coefficients of diffusion of substrate and metabolic products, initial concentration of mycelium and substrate, time of delay of mycelium reaction on metabolic products and spore formation, threshold concentration of metabolic products.
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