Magnetic Characteristics Research Articles

Enhancement the linear/nonlinear optical and magnetic properties of ZnCo2O4 nanostructures through Ni/Fe dual doping

Nano Zn0.9Ni0.1Co2-xFexO4 samples were prepared using the hydrothermal procedure in order to enhance the functional characteristics of ZnCo2O4 sample. The structural and microstructural parameters of the prepared samples were determined through Rietveld and FTIR analyses. The morphologies and compositions of the samples were examined by SEM and EDS techniques. Upon Ni2+ doping, the bandgap energy of nano ZnCo2O4 decreased from 2.22 eV to 3.61 eV–2.18 eV and 3.51 eV. Doping with Fe caused a slight decrease in bandgap energy for x = 0.05, then an increase for a higher content of Fe. Several empirical equations were used to determine the refractive index from the corresponding obtained optical energy gap values. As the Fe content rose to 5 %, the value of refractive index and nonlinear optical parameters increased; thereafter, it declined with additional Fe doping. The photoluminescence technique was used to analyze defects and processes of charge carrier recombination in the samples. ZnCo2O4 sample exhibits paramagnetic performance. With the addition of Ni to ZnCo2O4, the magnetic characteristics of the sample became superparamagnetic. Samples doped with Ni and various quantities of Fe exhibit a weak ferromagnetic behavior. The effect of doping on the magnetic transition, coercivity, saturation magnetization and remanent magnetization was explored.

Electrodeposition of MnAs-Based Thin-Film as a Possible Promising Candidate in Spintronics Applications

Abstract A thin film material obtained by Mn As co-electrodeposition was electrochemically deposited. Electrodeposition was chosen because is a versatile and easily scalable technique with low costs, and achievable under ambient conditions in water solution. These advantages are often unmatched by the typical production routes of spintronic materials. The use of different substrates was investigated, and the optimal deposition conditions were sought to reach the required morphology and composition, considering also the influence of pH and O2.
The deposition conditions were optimized using multivariate analysis. The samples were characterized morphologically, crystallographically, and compositionally with SEM-EDS, XRD, and XPS, suggesting that the deposit chemical composition was predominantly constituted by MnAs and MnO2. Magnetic characterization performed with a SQUID magnetometer showed that the sample disclose a ferromagnetic component. MnAs and MnO2 are known to have properties suitable for applications in spintronics, making this system interesting as an alternative for spintronic-based devices.

Soft Magnetic Characteristics and Magnetoimpedance Phenomenon in Copper Wire Coated with Permalloy Film Electroplated from a Sodium Gluconate-Based Bath

Soft Magnetic Characteristics and Magnetoimpedance Phenomenon in Copper Wire Coated with Permalloy Film Electroplated from a Sodium Gluconate-Based Bath

Exploring the Effect of Ce Doping on Structural, Magnetic Solar Cell and Optical Characteristics of Nano ZnMn2O4

Exploring the Effect of Ce Doping on Structural, Magnetic Solar Cell and Optical Characteristics of Nano ZnMn2O4

Detection method for structural defects of U-shaped hanging ring for power fittings based on magnetic leakage principle

The U-shaped hanging ring of electric power fittings is usually installed outdoors and operates in harsh environments. Under the combined effect of the weight of the conductor and wind load, the bending part at the bottom of the U-shaped hanging ring often experiences wear and cracks due to friction contact, which can easily lead to accidents such as the detachment of transmission lines. Traditional methods for detecting structural defects in ferromagnetic materials, such as ultrasonic testing, eddy current testing, and manual testing, are affected by environmental factors, have a shallow measurement depth, and are difficult to quantify. In order to solve the above problems, this paper proposes a measurement method for detecting structural defects in the U-shaped hanging ring of electric power fittings based on the principle of magnetic leakage. The magnetic leakage signal characteristics of U-shaped hanging ring defects under different excitation structural parameters and different defect types are analyzed. The method of arranging magnetic leakage signal measurement points is studied. The detection of defect parameters is achieved based on the characteristic quantity of the magnetic leakage signal under different defect conditions. Finally, the method is analyzed and verified through examples. The results show that this method can achieve quantitative detection of defect parameters in the U-shaped hanging ring under uniform structural defect and crack structural defect, and has the advantages of high measurement accuracy and small error. The research results of this paper can provide a scientific theoretical basis for the inspection and replacement of transmission line fittings in engineering, which is of great engineering significance for ensuring the safe and stable operation of the power grid.

Experimental research on combined magnetic separation and flotation for coal gasification fine slag

ABSTRACT To address the challenging issue of achieving high-precision carbon-ash separation in coal gasification fine slag, magnetic separation and flotation techniques were employed to study their respective separation effect. Optimization tests were conducted to determine the optimal magnetic field gradient and magnetic field intensity, and the ash content of magnetic separation concentrates was 72.18%, with a reduction of 7.28% compared to the sample. Additionally, the magnetic separation tailings exhibited an ash content of 93.99%. Through flotation tests, the optimum conditions for kerosene and composite collector was established. The ash content of flotation concentrates decreased by 16.39% compared to the sample, and the ash content of flotation tailings was 95.83%. A comparative analysis revealed that the combined separation process outperforms single separation methods in reducing the ash content of the concentrates, and realize the further quality improvement and separation effect. Detailed analysis of magnetic characteristics and XRD, XPS analysis studies on the sample and the products, indicated that the magnetic separation effectively pre-removes a certain amount of magnetic high ash minerals. Furthermore, the collector treatment significantly increased hydrophobicity difference between residual carbon and ash matter, which ultimately enhancing the flotation effect.

Study of magnetic, thermoelectric, and mechanical properties of double perovskites Be2XH6 (X = Cr and Mn) for spintronic and hydrogen-storage applications

Metal hydrides are highly significant for hydrogen storage because of high gravimetric and kinetic factors. Therefore, the double perovskites hydrides Be2XH6 (X = Cr and Mn) have outstanding hydrogen storage capability with gravimetric hydrogen densities of 7.9 wt% and 7.6 wt%, respectively. Moreover, the DFT-based PBE-GGA and TB-mBJ potential have been implemented to systematically analyze the electronic, Curie temperature, and magnetic characteristics of Be2XH6 (X = Cr and Mn). The tolerance factor and formation energy analysis indicate the structural and thermodynamic stabilities. The band structures, density of states and Curie Weiss law ensure the above room temperature half metallic ferromagnetism with complete spin polarization. The ultralow lattice thermal conductivity and high thermoelectric performance also significantly increase their importance. Finally, the mechanical and thermodynamic behavior have also been addressed in detail. These conclusions are significant for future hydrogen storage growth increases in metal hydrates.

Impact of Cu, Fe2O3, and Cu/Fe2O3 on the magnetic and structural characteristics of FeTiO2 nanocomposite synthesized through mechanical alloying processes

Impact of Cu, Fe2O3, and Cu/Fe2O3 on the magnetic and structural characteristics of FeTiO2 nanocomposite synthesized through mechanical alloying processes

Preparation and characterization of AChE immobilized magnetic bio-nanocomposites (Fe3O4@Cht/Au) for pesticide detection

Free enzymes cause difficulties in many applications due to their insufficient stability, loss of activity in a short time, and most importantly, although they are costly, they are used only once in reactions, lose their effect and cannot be recovered from the environment. Magnetic nanoparticles coated with biocompatible polymeric material are potential candidates for promising enzyme carriers due to their multifunctional pore surfaces, easy removal from the environment provided by the magnetization, ability to main stability under various harsh conditions. This study prepared a biosensor candidate based on the inhibiting acetylcholinesterase enzyme by organophosphate pesticides from chitosan-coated magnetic nanoparticles doped with gold. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction diffractometry, and Fourier transform infrared spectroscopy analysis confirmed the structure of synthesized nanocomposites. Magnetic characteristics of the nanocomposites were assessed using VSM. Bio-nanocomposite (Fe3O4@Cht/Au/AChE) was used to determine environmental pollutants qualitatively. Remediation of organophosphate-containing wastewater is an essential issue for environmental sustainability. In this work, Dichlorvos and Chlorpyrifos were selected as organic pollutants to assess the enzymatic activity of immobilized Fe3O4@Cht/Au/AChE. Optimum conditions for AChE enzyme were immobilized nanostructures (Fe3O4@Cht/Au/AChE) were determined. The optimum pH for the immobilized enzyme was found to be 8, and the optimum temperature was found to be 60 °C. Retained immobilized enzyme activity is found to be around 50% for the 20th reuse. In the presence of 150 µL pesticide, retained immobilized enzyme activity is found to be around 25%. Method validation was performed for pesticides. When using immobilized AChE, the LOD (limit of detection)-LOQ (limit of quantitation) values for Dichlorovos and Chlorpyrifos was obtained in the range of 0.0087–0.029 nM and 0.0014–0.0046 nM, respectively. The relative standard deviation (RSD%) values, which are indicators of precision, were found to be below 2%.

Monte Carlo study of magnetic properties of the fullerene C24 structure

ABSTRACT The fullerene C24 is one of the most active types of nanostructures and has been used as an active component in important applications. In this study, we investigated the magnetic characteristics of the mixed spins 5/2 and 3/2 of the Fullerene C24 system using Monte Carlo simulations. We start by offering a theoretical analysis of ground state phase diagrams. In fact, out of all potential configurations, we only present and analyze the stable configurations. Secondly, calculations are done to determine how the magnetic characteristics of this compound change as various physical parameters are changed. Additionally, we offer the examined magnetic behavior of the system with reduced temperature, reduced crystal field, reduced exchange-coupling interactions, and reduced external magnetic field. Finally, we looked into and talked about the critical reduced temperature of Fullerene C24. We showed and examined the hysteresis loops for various physical parameter values to end our work.

Nickel-doped magnetic carbon aerogel derived from xanthan gum: a competent catalyst for the degradation of single and binary dye-based water pollutants.

Toxic organic dyes (colorants) are one of the main causes of water pollution that releases destructive effluents in the environment. To overcome this issue, a fundamental need to produce a novel, efficient catalyst for the degradation and mineralization of dye mixtures has arisen. The objective of this research is to develop an eminent Ni-doped magnetic carbon aerogel (Ni-MCA) catalyst using graft co-polymerization method having xanthan gum as backbone doped with Ni-magnetic nanoparticles (Ni-MNPs), that do not show agglomeration and easy to separate. The examination revealed that Ni-MCA provided exceptional magnetic characteristics (Ms = 52.75emu/g) and potent catalytic activity for the degradation of mono- as well as binary-dye solutions of Congo red (CR) and methyl green (MG) dyes. The formation was verified by various characterization techniques such as FTIR, VSM, XRD, XPS, SEM, TEM, and EDX mapping. Interestingly, Ni-MCA shows faster result on anionic dye CR up to 97% with degradation rate of 5.647 × 10-1min-1, and MG dye shows degradation of 95.7% with the degradation rate of 2.169 × 10-1min-1, while dye mixture is showing 90% degradation with rate of 2.159 × 10-1min-1.

Exploring the Mn doped BaTe alloy for spintronics and energy harvesting applications

In the present study, the ferromagnetic semiconductor behavior of Mn doped BaTe is reported along with their physical properties. The calculations are done by full potential linearized augmented plane wave (FP-LAPW) approach within spin-polarized density functional theory (SP-DFT). Formation energies were computed to satisfy the stability of reported alloys. The spin-polarization is included in the calculations to study the electronic (band structure (BS), density of states (DOS)) and magnetic characteristics. Ba1−xMnxTe elucidates the magnetic semiconductor nature with direct band gap (Eg) in both spin channels while indirect Eg (1.66 eV) is observed for pure BaTe compound. Stable ferromagnetic (FM) states are vindicated owing to the p-d hybridization which are contributors in inducing magnetic moments (μ B) at interstitial and non-magnetic sites. The optical parameters (reflectivity, absorption coefficient, refraction, optical conductivity and dielectric function) were computed within an energy range of 0–10 eV. Thermoelectric (TE) features are also figured using Boltaz-Trap code in terms of thermal and electrical conductivity, figure of merit, Seebeck coefficient and power factor. The analysis of optical parameters suggests that the considered alloys is active within visible to UV-range, having potential applications in optoelectronic, photovoltaic and thermoelectric applications.

Key postnatal magnetic resonance characteristics for differentiating cystic biliary atresia from choledochal cyst.

To analyze the ability of magnetic resonance (MR) to identify cystic biliary atresia (CBA) and choledochal cyst (CC). Infants (≤ 1 year old) who were diagnosed with CBA or CC type I/IV from January 2010 to July 2023 were retrospectively reviewed. Imaging characteristics on MR were compared between the CBA and CC groups. Binary logistic regression and the area under the receiver operating characteristic curve (AUC) were analyzed for the identification of CBA. Sixty-three patients with CBA (median age, 30 days) and 172 patients with CC (median age, 60 days) were included. Gallbladder (GB) wall thickness (cutoff, 1.2 mm) showed 98.4% sensitivity and 100% specificity (AUC, 0.998). MR-triangular cord thickness (MR-TCT) (cutoff, 4.1 mm) showed 100% sensitivity and 95.9% specificity (AUC, 0.986). The bile duct loop visualization showed 96.8% sensitivity and 100% specificity (AUC, 0.984). Proximal bile duct (PBD) diameter (cutoff, 1.3 mm) showed 92.1% sensitivity and 95.3% specificity (AUC, 0.977). Cyst wall thickness (cutoff, 1 mm) showed 77.8% sensitivity and 95.3% specificity (AUC, 0.942). The combination of GB wall thickness > 1.2 mm and MR-TCT > 4.1 mm, GB wall thickness > 1.2 mm and loop visualization, GB wall thickness > 1.2 mm, and cyst wall thickness > 1 mm showed 100% sensitivity and 100% specificity (AUC, 1.000). Imaging characteristics on MR might be used to identify CBA and CC, and the combination of GB wall thickness and MR-TCT, or loop visualization, or cyst wall thickness, has a perfect diagnostic value. Early and accurate differentiation of CBA and CC is essential, but current methods rely on inherently subjective ultrasound. Biliary features on MRI allow for an objective, accurate diagnosis.

Online Measurement Method and System of Excitation Impedance of Current Transformers Based on Norton's Theorem and Differential Method to Measure Difference of Two Currents.

An online measurement method is proposed in this paper, and a system is established for detecting the excitation impedance of current transformers (CTs) based on Norton's theorem. The theorem is carried out by connecting a resistance and an inductance at the secondary side port of the CT to get the equations for calculating the impedance. The iterative method is used to solve the equations, and the solution is revised to consider the nonlinearity of the core. The main variable in the equations is the variation of the secondary current with the resistance or inductance. To obtain the secondary current variation accurately, which is less than 1‱ of the current, a differential method is proposed, which is based on charging two capacitors and measuring the difference of their voltages instead of measuring each current separately first and then obtaining the current variation by subtraction. This is equivalent to saving two currents first and then measuring the current difference. The differential method avoids the problem of error amplification in the process of measuring two currents separately first and then subtracting them to obtain the current variation and solves the problem that two currents do not appear simultaneously. The results verify the correctness and accuracy of the proposed method and system. The acquisition of the excitation impedance is the basis for obtaining the working characteristics of CT cores, including magnetic and loss characteristics, as well as the error of CTs.

The SF and remanence evaluation of magnetic shields based on SST for low frequency and degaussing situation

Abstract The permalloy sheet, as the dominant shielding functional material, mainly determines static and low frequency shielding performance of magnetically shielded room (MSR). However, lack of measurement of shielding sheet in practical use would lead to the nonnegligible evaluation error for MSR performance. Therefore, an estimation technique of shielding factor (SF) and the remanence of MSR is proposed in this paper with the consideration of the nonlinear magnetic characteristics of the permalloy sheet tested by single sheet tester for low frequency field and degaussing situation(L-D-SST). First, a high-accuracy measurement system, composed of L-D-SST (for exciting magnetic field and sensing the corresponding B and H) and the control system (for applying excitation to L-D-SST and amplifying, filtering and collecting B and H signal), is established. The weak magnetic fields of low frequencies and decaying alternating demagnetizing field excitations are separately applied to L-D-SST for basic magnetization curves (BM curves) and anhysteretic magnetization curve (AM curve) test. Furthermore, the BM and AM curves are respectively integrated with FEM algorithm for the accurate and reliable estimation of the SF and remanence of MSR in operation state. In addition, the tested magnetic properties are applied to the optimization of MSR shielding quality.

Exploration of dynamic phase transition of 3D Ising model with a new long-range interaction by using the Monte Carlo method

In this paper, we present a novel interpretation of the long-range interaction for exploring the magnetic characteristics of the 3D Ising model. To describe the long-range interaction, we utilize spin chains, which enable us to explore the dynamic magnetic behaviors of this model. The research investigates the impacts of the amplitude of the time-dependent magnetic field h0 and period τ on the dynamic phase transition by obtaining phase diagrams and midplane cross-sections of the system. Critical exponents are also discussed, which are consistent with other theoretical results. The dynamic hysteresis behaviors are then examined through various physical parameters. As the temperature increases, the area and shape of the dynamic hysteresis loop change. Our theoretical conclusions are consistent with those of other theoretical and experimental studies.

Epitaxial growth, structural and magnetic characterization of thulium thin films

Epitaxial growth, structural and magnetic characterization of thulium thin films

Sonographic Appearance of the Ischiocondylar Origin of the Adductor Magnus.

The adductor magnus ischiocondylar origin (AM-IO) tendon has often been described as a third proximal hamstring tendon due to its common origin on the ischial tuberosity as well as similar function. Prior studies have described the magnetic resonance imaging characteristics of the AM-IO; however, its appearance on ultrasound has not been well-detailed. The purpose of our study is to describe the sonographic appearance of the AM-IO and provide a structured scanning protocol for complete evaluation of the tendon.

Three-dimensional electrochemical-magnetic-thermal coupling model for lithium-ion batteries and its application in battery health monitoring and fault diagnosis

Storage batteries with elevated energy density, superior safety and economic costs continues to escalate. Batteries can pose safety hazards due to internal short circuits, open circuits and other malfunctions during usage, hence real-time surveillance and error diagnosis of the battery’s operational state is imperative. In this paper, a three-dimensional model of electrochemical-magnetic field-thermal coupling is formulated with lithium-ion pouch cells as the research focus, and the spatial distribution pattern of the physical field such as magnetic field and temperature when the battery is operational is acquired. Furthermore, this manuscript also investigates the diagnostic methodology for defective batteries with internal short circuits and fissures, that is, the operational state of the battery is evaluated and diagnosed by the distribution of the magnetic field surrounding the battery. To substantiate the method’s practical viability, the present study extends its examination to the 18650-battery pack. We obtained the magnetic field images of the normal operation of the battery pack and the failure state of some batteries and analyzed the relationship between the magnetic field distribution characteristics and the performance of the battery pack, providing a new method for the health monitoring and fault diagnosis of the battery pack. This non-contact method incurs no damage to the battery, concurrently exhibiting elevated sensitivity and extremely rapid response time. Meanwhile, it provides an effective means for non-destructive research on the batteries and can be applied to areas such as battery safety screening and non-destructive testing. This research not only helps to facilitate our understanding of the battery’s operating mechanism, but also provides robust support for safe operation and optimal battery design.

Synthesis, Crystal Structure, and Optical and Magnetic Properties of the New Quaternary Erbium Telluride EuErCuTe3: Experiment and Calculation.

This paper reports for the first time on a new layered magnetic heterometallic erbium telluride EuErCuTe3. Single crystals of the compound were obtained from the elements at 1120 K using CsI as a flux. The crystal structure of EuErCuTe3 was solved in the space group Cmcm (a = 4.3086(3) Å, b = 14.3093(9) Å, and c = 11.1957(7) Å) with the KZrCuS3 structure type. In the orthorhombic structure of erbium telluride, distorted octahedra ([ErTe6]9-) form two-dimensional layers (Er(Te1)2/2e(Te2)4/2k-)∞2, while distorted tetrahedra ([CuTe4]7-) form one-dimensionally connected substructures (Cu(Te1)2/2e(Te2)2/1t5-∞1) along the [100] direction. The distorted octahedra and tetrahedra form parallel two-dimensional layers (CuErTe32-∞2) between which Eu2+ ions are located in a trigonal-prismatic coordination environment (EuTe610-). The trigonal prisms are connected by faces, forming chains (Eu(Te1)2/2(Te2)4/22-∞1) along the [100] direction. Regularities in the variations in structural parameters were established in the series of erbium chalcogenides (EuErCuCh3 with Ch = S, Se, and Te) and tellurides (EuLnCuTe3 with Ln = Gd, Er, and Lu). Ab-initio calculations of the crystal structure, phonon spectrum, and elastic properties of the compound EuErCuTe3 were performed. The types and wavenumbers of fundamental modes were determined, and the involvement of ions in the IR and Raman modes was assessed. The experimental Raman spectra were interpreted. The telluride EuErCuTe3 at temperatures below 4.2 K was ferrimagnetic, as were the sulfide and selenide derivatives (EuErCuCh3 with Ch = S and Se). Its experimental magnetic characteristics were close to the calculated ones. The decrease in the magnetic phase transition temperature in the series of the erbium chalcogenides was discovered.