For spintronic devices, the adsorption of transition metal (TM) atoms may provide two-dimensional (2D) materials with enhanced electrical and magnetic characteristics. Herein, the stability, electronic, and magnetic properties of 4d (Ag, Cd) and 5d (Ir, Pt, Au, Hg) TM adsorbed mono-layer antimonene (Sb) are investigated thoroughly using first-principles calculations. We find out the stability and suitability of the material by using different parameters like relative formation energy, thermal stability, and phonon dispersion curve. The adsorption energies suggest that the most favorable position of adsorption is the hollow (H) site where the ground state energy is lowest. In the case of Ir, and Au adsorbed Sb, the metallic and magnetic behavior is observed due to the change of spin-up and down. Adsorption of Ag also reveals metallic behavior but there is symmetry in high and low spin and shows non-magnetic results. Interestingly, the spin-polarized semiconducting state appears in Cd, Pt, and Hg adsorbed Sb and shows non-magnetic semiconductor behavior. Our study reveals that the TMs adsorbed Sb can be used in potential applications like spintronics, magnetic storage devices, optoelectronics, and Nanoelectronics applications.

Fe83SixByC(17-x-y) has good glass forming ability (GFA), and high saturation magnetic induction (Bs), and spherical amorphous powder can be prepared using a gas–water coupling atomization (GWC) device. Herein, the effects of metalloid elements (B, C, Si and P) on the thermal parameters and magnetic properties of the Fe83SixByC(17-x-y) powder are discussed. The research conclusion shows that the Fe83Si2.5B11.5C3 amorphous powder exhibits the best comprehensive performance. Through the Lorentz microscope pattern of Fe83Si2.5B11.5C3 amorphous powder, magnetic domains walls are observed to gather and interlace in the outer region of the particle. The Fe83Si2.5B11.5C3 amorphous powder exhibits a high initial crystallization temperature (Tx1), followed by a ΔTx of 27 ℃, and then crystallization completion at 561.1 ℃. Some clusters or primary crystals are produced in the amorphous matrix after annealing at 520 ℃ (below Tx1 534 ℃) for 1 h. A further increase in the annealing temperature to 570 ℃ (beyond Te1 561.1 ℃) causes the precipitation of a large amount of crystalline phase α- Fe (Si) and hard magnetic phase Fe2B, thereby resulting in the rapid deterioration of the magnetic properties of the amorphous powder.

Hexagonal MnSb is a ferromagnet with Curie temperature and saturation magnetization values of 587 K and 110 emu/g, respectively. In this paper, the origin of the complex magnetic behavior of a single phase MnFe0.20Sb prepared using solid-state reaction method is examined. A thorough investigation of temperature dependent magnetization and magnetic relaxation measurements reveals the presence of a glassy like phase below 15 K. AC susceptibility measurements revealed the existence of a cluster glass-like state with a freezing temperature of 18 K. The presence of competing magnetic interactions and random occupation of Fe atoms at 2d site leads the system to exhibit a cluster glass state. Furthermore, resistivity measurements indicate that the material exhibits a Kondo-like behavior below 30 K and can be attributed to the interaction of conduction electrons with localized Mn moments.

To explore the effect factors on the fluidity of magnetic fluid at low temperatures, the magnetic fluid was prepared by dispersing stearic acid and oleic acid-modified particles into kerosene, the effect of volume fraction was also considered. The microstructure and morphology of the particles were obtained by XRD and TEM, and the surfactant content on the surface of the particles was determined by TG. The hysteresis loops of magnetic particles and magnetic fluids were obtained by VSM. As the temperature decreased, it was observed that the magnetic fluid with a high volume fraction of stearic acid-modified particles would lose fluidity quickly under a non-magnetic field. But it could respond to a certain magnetic field, and the fluidity could be restored quickly by increasing the temperature. The rheometer measured the viscosity of the magnetic fluid-dependent temperature, shear rate, and magnetic field. When a high melting point of stearic acid coated particles, the stearic acid with adequate chain length could affect the fluidity of magnetic fluid with a volume fraction greater than 5% at roughly 20 °C. The free surfactant formed micelle, the base carrier was restricted in the particles adhering to the micelles, eventually causing the magnetic fluid to lose fluidity.

This research aims to investigate the thermal performance of a hybrid nanofluid consisting of aluminum oxide and copper Al2O3−Cu nanoparticles on the uniform (50%50%) flow of two different fluids such as water and ethylene glycol H2O−C2H6O2 over a permeable cylinder. To conduct the study, three different hybrid nanoparticle shapes (cylinder, brick, and blade) are taken into consideration. The momentum relationship is derived by taking into account porosity and Darcy–Forchheimers effects. Energy communication is formulated by including joule heating, radiation, and viscous dissipation effects. Boundary layer approximations are used to obtain the partial differential equations (PDEs) governing the system, which are then transformed into ordinary differential equations (ODEs) using the appropriate transformations. The equations are solved using the bvp4c MATLAB solver. The study discovers that for all nanoparticle shapes, the velocity field of the hybrid nanofluid decreases with increasing porosity parameters, Hartmann numbers, and inertia factors. The Prandtl number and stratification parameter cause the fluid temperature of the hybrid nanofluid to decrease for all shapes, whereas Eckert and Hartmann’s numbers have the reverse effect. The skin friction and Nusselt numbers are also computed and presented on graphs for various nanoparticle forms.

Topology applied to condensed matter is an important area of research and technology, and topological magnetic excitations have recently become an active field of study. This paper presents a general discussion of magnon Hall transport in two-dimensional antiferromagnets. Although the Chern number is zero for a collinear antiferromagnet, we offer a general discussion that can be used in the more general case. First, we study the Union Jack lattice, where an effective time-reversal symmetry is broken, making the system display the magnon Hall effect. Then, we investigate the brick-wall lattice where such symmetry is present. Consequently, we have a phenomenon similar to the quantum spin Hall effect in electronic systems. Both lattices have not yet been studied from the topological point of view. The coexistence of opposite spin polarization in an antiferromagnet resembles the electron spin in various transport phenomena. We study magnon transport in the lattices mentioned above with Dzyaloshinskii-Moriya interaction and easy-axis single-ion anisotropy. We calculate the Berry curvature from the eigenvalues of the Hamiltonian. From that, we plot the spin Hall and thermal Hall conductivities, as well as the spin Nernst coefficient, as functions of the temperature. In the Union Jack lattice, we treat the effect of anharmonic interactions using a mean-field spin wave theory where the Hamiltonian becomes implicitly temperature-dependent. We determine self-consistently the renormalized dispersion and the staggered magnetization as a function of temperature. Our calculations can be applied to other antiferromagnetic lattices.

This article presents a comprehensive evaluation of a new residual stress reduction method based on magnetic-vibration stress relief treatment for cold-rolled DP590 high-strength steel plate. The effectiveness of magnetic-vibration stress relief treatment is compared to that of other treatment methods such as vibration treatment alone, magnetic treatment alone, and sequential combinations of vibration and magnetic treatment. The experimental results indicate that magnetic-vibration stress relief treatment is more effective than other methods in reducing residual stress. Specifically, magnetic-vibration stress relief treatment reduces transverse residual stress by approximately 39.42% and longitudinal residual stress by approximately 54.52%. In contrast, single vibration treatment reduces transverse residual stress by approximately 19.65% and longitudinal residual stress by approximately 19.31%, and single magnetic treatment reduces transverse residual stress by approximately 18.16% and longitudinal residual stress by approximately 7.12%. Theoretical analysis based on first principles reveals that ferromagnetic materials exhibit a stress-magnetic effect that can be exploited to soften and deform the material, leading to enhanced reduction effects during magnetic-vibration stress relief treatment.

The perpendicularly magnetized synthetic antiferromagnets (SAFs) are expected to be ideal materials for magnetic random-access memory (MRAM) due to the low cross-talk noise and the high recording density. Normally, an in-plane magnetic field is required to break the inversion symmetry for deterministic magnetization switching in perpendicular SAFs by SOTs, which is undesirable for applications. In this work, the ion-irradiation method was adopted to engineer the interface of a perpendicularly magnetized Pt/Co/Pt/Ru/Pt/Co/Ta SAF to achieve the filed-free switching of the magnetization via the in-plane magnetization component of top-Co layer, which provides an in-plane effective field to bottom-Co layer and breaks the symmetry. Furthermore, with the increase of ion fluence, the critical switching current density decreases, which is consistent with the increase of spin Hall angle induced by ion-irradiation measured by the harmonic Hall voltage method. These results indicate that ion irradiation is a promising approach for realizing field-free magnetization switching in SAFs driven by SOTs and has potential application in SOT-based spintronic devices.

LnSbTe (Ln – lanthanide) group of materials, belonging to ZrSiS/PbFCl (P4/nmm) structure type, is a platform to study the phenomena originating from the interplay between the electronic correlations, magnetism, structural instabilities and topological electronic structure. Here we report a systematic study of magnetic properties and magnetic structures of LnSbTe materials. The studied materials undergo antiferromagnetic ordering at TN = 2.1 K (Ln = Er), 6.7 K (Ln = Dy), 3.1 K (Ln = Nd). Neutron powder diffraction reveals ordering with k1 = (½ + δ 0 0) in ErSbTe, k2 = (½ 0 ¼) in NdSbTe. DySbTe features two propagation vectors k2 and k4 = (0 0 ½). No long-range magnetic order is observed in PrSbTe down to 1.8 K. We propose the most probable models of magnetic structures, discuss their symmetry and possible relation between the electronic structure and magnetic ordering.

In this paper, a mathematical model for the dynamics of superparamagnetic iron oxide nanoparticles (SPIONs) in a laminar flow through a pipe under the influence of an external magnetic field of a single electromagnet is derived. The model consists of a convection–diffusion equation coupled with magnetostatic equations. The accumulation of particles along the boundary is modeled with the help of a surface concentration. Based on experimental data describing the retention of lauric acid coated SPIONs in a tubular flow under the influence of a magnetic field, the model is parametrized and finite element simulations are performed. With the exception of one outlier at low SPION concentration and high flowspeed, the simulation results agree very well with the experimental measurements within the bounds of the measurement error.

In current research, the physical characteristics of the laminar steady boundary layer flow of CNTs/ C2H6O2+H2O hybrid base nanofluid across a permeable exponentially contracting surface along the influence of magnetic force, heat radiation, and velocity slip of the first order have been examined. The effect of magnetic field stability analysis on the hybrid-based nanofluid flow of CNTs with thermal radiation was not previously explored for the numerous solutions, which is the originality of the current work. The partial differential equations (PDEs) controlling the model were transformed to ordinary differential equations (ODEs), and then the ODEs were solved using the three-stage Lobatto IIIa numerical approach in the MATLAB program. For different nanofluids constituted of SWCNTs and MWCNTs as nanoparticles and C2H6O2+H2O as the hybrid base nanofluid, the impacts of changes in the values of various parameters on temperature, velocity, heat transfer, and skin friction coefficient profiles were explored. Tables and figures illustrate numerically and quantitatively the outcomes. In addition to the effects of outputs, there are two solutions within the range of suction parameter. In addition, the parameter ∅ has a diminishing influence on heat transfer rate and skin friction coefficient in the first solution, resulting in a decrease in the surface drag force and heat transfer rate. Moreover, the selection of nanoparticle kinds has a substantial effect on the cooling/heating processes and stream function. Finally, a linear temporal stability analysis was performed to classify the stable solution among the dual solutions.

Magnetic nanodisks and nanorings have been focus of attention for quite some time due to their applicability in magnetic memory devices. In this paper, static and dynamic magnetic properties of Permalloy concentric thin ring nanostructures are reported as a function of the number of rings by using micromagnetic simulations. The maximum outer radius (R) and thickness (t) of the concentric rings are fixed at 100 nm and 20 nm respectively. The distance between any two neighbouring rings is always maintained equal to the width of each ring while the number of nanorings is increased starting from one to five. In-plane magnetic hysteresis loops show that in all cases, the remanence and coercivity values are found to be almost zero while vortex state is exhibited with opposite helicity in adjacent nanorings. When the number of nanorings reach five, the narrowest hysteresis loop is observed with almost no hysteresis at all. Dynamic susceptibility spectra was computed by relaxing the system from a out of plane saturated state followed by an in-plane excitation using a small field pulse. In most of the cases, the in plane magnetic field pulse excites azimuthal spin wave modes. The resonance frequency corresponding to these excitation modes depends on the remanent configuration and the number of peaks increase with increment in the number of rings. The ferromagnetic resonance mode that is common for all the samples considered, moves towards lower frequency with increase in number of concentric rings.

The study of mutual interaction between flow and external magnetic field, as well as the influence of temperature on the motion, is crucial for new classes of materials involved in nanotechnologies. This paper considers a very common situation where a hybrid nanofluid fills a vertical plane channel with a moving wall. Since the nanofluid is Boussinesquian the flow is induced by the buoyancy and Lorentz forces together with a constant pressure gradient. This problem has many industrial applications so that it is of relevant interest. Using a steady and laminar flow, an exact solution for the ODEs which govern the motion has been found. This is the first time an analytical solution is developed for the problem here considered. Analytical expressions for velocity profile and magnetic field are exhibited graphically. Effect of parameters on the flow characteristics has been discussed also in the case of some real hybrid nanofluids (H2O with Al2O3 and Cu, H2O with Ag and MgO, C2H6O2 with TiO2 and Fe3O4). We also find that the presence of two different types of particles determines an increase in the velocity of the nanofluid in accordance with experimental studies. As usual the presence of the external magnetic field causes a decrease in the velocity. Finally, the reverse flow phenomenon is discussed.

In the present paper, Hall current and Soret reaction effects on unsteady natural convection MHD flow with viscous, incompressible, and electrically conducting fluid through a porous medium in the presence of chemical reaction and thermal radiation have been studied. The fluid has considered non-Newtonian fluid, which is Jeffrey fluid. The non-dimensional flow governing equations are solved analytically through the perturbation method, and obtained results of velocity, concentration, and temperature have been analyzed with the help of graphs drawn for different parameters. The numerical values of skin friction, Nusselt number, and Sherwood number have been tabulated. The study's results may find applications related to solar physics dealing with the solar cycle, Magnetohydrodynamics sensors, rotating MHD induction machine energy generators, sunspot development, the structure of rotating magnetic stars, etc. The velocity profiles are observed to increase with an increase in Hall parameters, but reverse effects are found with an increase in viscosity ratio and chemical reaction parameter. The thermal radiation parameter is to increase the temperature profiles, but the reverse effect is observed with an increase in the frequency of oscillations. Further, the concentration is decreased with an increase in the Schmidt number and increased with an increase in the chemical reaction parameter.

The successful production of nanopowders consisting of Ho-doped zinc ferrite (ZnFe2-xHoxO4, with x values ranging from 0 to 0.08) has been accomplished using the glycine-nitrate combustion (GNC) method, followed by calcination in air. Various analytical techniques, such as EDXS, DTA-TG, SEM, PXRD, Raman spectroscopy, and vibrating sample magnetometry (VSM), were employed to examine the resulting samples. The outcomes of our investigation indicated that an excess of fuel during the GNC process yields X-ray amorphous foamy products, which subsequently crystallize after being held at a temperature of 550 °C for a duration of 4 h. PXRD data analysis showed that the obtained samples consist of single-phase Ho-doped zinc ferrite with a spinel structure. The incorporation of holmium into the ferrite spinel structure was established to occur when the calcination temperature is elevated to 700 °C. Rietveld refinement revealed that the degree of inversion varies from 0.078 to 0.309 as the level of Ho-doping increases from x = 0 to x = 0.08. Furthermore, the incorporation of Ho leads to a more than twofold reduction in the crystallite size of ZnFe2-xHoxO4, decreasing from 61.7 to 27.3 nm. The magnetic properties of the nanopowders are shown to be systematically altered by changes in the degree of inversion and the crystallite size of zinc ferrite, which are interrelated with the holmium content. For instance, the saturation magnetization (Ms) increases by 20% and attains a value of 54.9 kOe at x = 0.08. This finding suggests that the magnetic behavior of ZnFe2–xHoxO4 nanoparticles can be deliberately adjusted, making them a promising candidate for functional materials in the field of magnetic hyperthermia. In summary, this research provides valuable insights into the synthesis, structure, and magnetic properties of Ho-doped zinc ferrite nanopowders, underscoring their potential applications in the realm of magnetic hyperthermia.

Magnetoelectric (ME) coupling in multiferroic materials plays an important role in designing multifunctional devices because of their potential to tune polarization via a magnetic field or magnetism via an electric field. However, the single-phase ME materials have not been successfully explored in practical devices due to their low ME coupling coefficient. Here, we optimized the magnetic and magnetoelectric response of single-phase Bi1-xYxFe0.7Mn0.3O3 compounds by controlling the Y substitution and sintering temperature. Single-phase Bi1-xYxFe0.7Mn0.3O3 (where x varies from 0 to 0.20 in the step of 0.05) compounds were prepared by a standard solid-state reaction technique. The optimum sintering temperature and yttrium substitution were found to be 825 °C and x = 0.10, respectively, in which the sample shows the optimum microstructural, magnetic, and ME properties at room temperature. The optimized Bi0.9Y0.1Fe0.7Mn0.3O3 compound shows uniform growth of grains with less porosity, maximum remanent magnetization (∼0.012 emu/g), and enhanced ME coupling coefficient (35 mV/Oe.cm.). The ME coupling coefficient obtained from the optimized sample is six times higher than that of the pristine sample. This work provides a potential route for improving the ME coupling coefficient in BiFeO3-based multiferroic materials for practical applications.

Controlling the magnetic anisotropy of thin magnetic films with in-plane magnetization is of highest relevance particularly for magnetic field sensors. Here, the origin and magnitude of the in-plane magnetic anisotropies of ferromagnetic Co20Fe60B20 films with obliquely sputter-deposited Ta-seed layers are investigated. Uniaxial in-plane anisotropy constants in the range of a few kJ/m3 up to about 25 kJ/m3 become accessible. We find that the anisotropy is predominantly determined by an surface rather than the bulk term. However, the magnetostatic effects arising from the measured directional roughness of the Ta seed cannot fully account for the observed anisotropy, indicating the existence of an additional origin of the anisotropy arising from the oblique sputtering. Further, we find that the anisotropies of films deposited with normal incidence in an applied magnetic field are about an order of magnitude weaker. Overall, this work shows that oblique sputtering offers a strategy to induce in plane anisotropies of up to 25 kJ/m3 in CoFeB, however, at the expense of larger Ta seed thickness.

Monte Carlo simulations are used to investigate the magnetic properties of the nanostructured spin-7/2 and spin-1 ferrimagnetic bilayers within interlayer exchange interactions. The effects of nonmagnetic layers thickness, magnetic coupling and the crystal field on the blocking temperature, magnetization and hysteresis loops are studied. It is found that the blocking temperature decreases when increasing the magnetic coupling between layers and/or increasing the thickness of the magnetic layer. Besides, the model exhibits multiple hysteresis loops for which the area decreases when increasing the thickness of the magnetic layer, the crystal field and/or the temperature. Moreover, the effect of temperature on the behavior of the partial and the total magnetization and the total susceptibility are also as investigated.

Magnetic interactions of [Co/Cr]n/IrMn and [Fe/Pt]n/IrMn multilayers grown by magnetron sputtering were investigated by ferromagnetic resonance (FMR) and magnetometry. The phenomenological model used to determine the magnetic anisotropies parameters from the FMR data also revealed the presence of a rotatable anisotropy in the samples studied. The rotatable anisotropy field in [Co/Cr]n/IrMn multilayers can be associated to antiferromagnetic coupling between the Co and Cr layers, while in the case of [Fe/Pt]n/IrMn multilayers, the polarization of Pt atoms may account for the negative rotatable anisotropy.

The main aim of this study is to investigate the significance of activation energy in the flow of a Maxwell fluid over a stretching cylinder. Additionally, the heat and mass fluxes of viscoelastic Maxwell fluids, thermal radiation, porous media, Brownian motion, heat generation/absorption, and thermophoresis over a stretching cylinder porous media containing gyrotactic microorganisms are also discussed in the flow. The governing nonlinear PDEs were converted into ODEs using similarity transformation. The transformed ODEs are tackled numerically by employing the Bvp4c scheme. This method contains a three-stage Lobatto IIIa collocation formula that provides continuous solutions up to fourth-order accuracy. Impacts of all physical parameters are illustrated in the form of graphs. The emerging parameters of the surface friction and heat/mass flux coefficients were tabulated. The results showed that the temperature and associated boundary layer thickness decreased with higher heat generation/absorption parameter values. Increasing the radiation parameter improves the temperature of the fluid, and increasing the activation energy parameter improves the thickness of the concentration boundary layer. The results of our research were compared with those of the existing literature and found to be in good agreement.