Magnetic Values Research Articles

Synthesis and Characterization of InGaZnO Nanocomposites: An Insight of Optical, Dielectric, and Magnetic Properties

In this study, pure Indium oxide (In2O3 100%) and its composite films Indium gallium oxide (IGO 50%:50%), and Indium gallium zinc oxide (IGZO 33%:33%:34%) are deposited on glass substrate by Sol-gel dip coating method. Indium oxide and its composites have a high degree of crystallization, as evident by the strong diffraction peaks. The SEM images depict distinctly diverse morphologies of nanostructures varied in size from 22.2nm to 138nm. The wider band gap (Eg) engineering (reported (Eg≈ 3.62eV)–In2O3, (Eg ≈ 3.83eV)–IGO, (Eg≈3.74eV) –IGZO) and heterostructure formation is also advantageous for novel In2O3 applications in advanced (transparent) devices and sensors. Complex impedance analysis provides insights into the grains and grain boundaries of In2O3 and its composite films (IGO, IGZO). The VSM measurements confirms that IGZO has a higher saturation magnetization value of 13.33emu/cm3 and a lower coercivity value of 429.54Oe as compared to In2O3 and IGO highlighting their magnetic properties suitable for spintronic and high-frequency device applications.

Synergetic effect of Hexaferrite and reduced Graphene oxide (rGO) in Photothermal therapy and Hyperthermia applications

This research article describes the synthesis of composite materials by combining T-type hexagonal ferrite and reduced Graphene Oxide using the standard ceramic process. The Calcium-based T-type hexagonal ferrite was synthesized by using the sol-gel auto-combustion method whiles the reduced graphene oxide by adopting the Hummer method. The crystallite size varied in the range of 34.11 to 42.07nm as calculated from the X-ray diffraction (XRD) data. Consequently, the lattice parameters 'a' and 'c' decreased from 5.9 to 5.1Å and from 29.92 to 28.32Å, respectively. The use of atomic force microscopy (AFM) revealed a range of particle sizes at the surface, varying from 1.70nm to 3.85nm. Moreover, the saturation and remanence magnetization values demonstrated an increasing trend with T-type hexaferrites concentration whereas the coercivity decreased. The UV-vis near-infrared spectra exhibited substantial light absorption, characterized by a wide absorption range in the visible and near-infrared (NIR) region (700 to 1100nm) which indicates its use in Photothermal therapy (PTT). The Calcium T- type hexaferrite exhibited clear peaks in the blue, green, violet, and yellow spectra in its photoluminescence (PL) properties. These peaks are believed to be caused by oxygen vacancies and defects. The synthesized samples displayed a lossy behavior in the polarization-electric field (P-E) loop, with saturation polarization levels exceeding remnant polarization, which is an amenable condition for lossy behavior. Most importantly, the synthesized materials had significant thermal responses when exposed to an alternation (AC) magnetic field, indicating their potential use in magnetic hyperthermia applications.

Effect of anisotropy field on the resonance frequency and reflection loss shift characteristics of barium hexaferrite ceramics

Abstract For this study, a modified barium hexaferrite based microwave and radar absorbing material was used. Synthesis and characterization of BaFe(12−2x)(MnTi) x O19 (0.1 ≤ x ≤ 1.0) have been prepared by solid state reaction method. The x-ray diffraction patterns reveal that all samples only crystallized into M-type barium hexaferrite after calcination at 1200 °C. Surface morphology images show that the hexagonal flake-like particle is formed at the initial stages of the Mn-Ti substitution level. The magnetic properties measurement reveals that the variation of magnetization values may vary based on preferable site occupation of Mn4+-Ti2+ cations to replace Fe3+ cations. The significant decrease in coercive field (H c) from 3.18 kOe to 0.51 kOe with the increase of Mn-Ti substitution affected the lowering values of anisotropy field (H a ). The maximum reflection loss (RL) positions of BaFe(12−2x)(MnTi) x O19 compositional series are shifted to lower frequency range following the H a trendlines. The maximum RL value equals to 98.42% microwave absorption at 10.5 GHz has been obtained in x = 1.0 (BaFe10Mn0.5Ti0.5O19) composition.

Field‐based estimation of cation exchange capacity using induced polarization methods

AbstractThis study investigates the potential of field‐based induced polarization (IP) methods to provide in‐situ estimates of soil cation exchange capacity (CEC). CEC influences the fate of nutrients and pollutants in the subsurface. However, estimates of CEC require sampling and laboratory analysis, which can be costly, especially at large scales. Induced polarization (IP) methods offer an alternative approach for CEC estimation. The sensitivity of IP measurements to the surface properties of geological materials ought to make them more appropriate than DC resistivity and electromagnetic induction methods, that are sensitive to bulk electrical properties . Such abilities of IP are well demonstrated in the laboratory; however, applications are lacking at field scales. In this work, the ability of field‐based IP to characterize the CEC of floodplain soils is assessed by implementing a methodology that allows for direct comparison between IP and soil parameters. In one field, soil polarization and CEC exhibited the expected positive correlation; but multi‐frequency measurements showed no clear advantage over single‐frequency measurements. In another field, coarser soils (with low CEC) exhibited a high polarization. These coarser soils were characterized by anomalous magnetic susceptibility values, and hence the polarization was attributed to the presence of magnetic minerals. Although better than order‐of‐magnitude estimates of CEC were possible in soils without substantial magnetic minerals, better characterization of porosity, saturation, cementation and saturation exponents, and pore fluid conductivity would improve predictions. However, the measurement of these parameters would require similar efforts as direct CEC measurements. This study contributes to bridging the gap between laboratory‐derived relationships and their applicability in field applications. Overall, this work provides valuable insight for future studies seeking to understand polarization mechanisms in soils at the field scale.

Functional recycling of grain boundary diffusion processed Nd-Fe-B sintered magnets

Sintered Nd-Fe-B magnets industrially produced employing the grain boundary diffusion process (GBD) were recycled by the so-called functional or short-loop recycling approach, based on hydrogen decrepitation (HD). Microstructural and magnetic differences between the original and the recycled materials were analyzed. The functional recycling of GBD magnets leads to the dissolution of the core (heavy rare earth lean) - shell (heavy rare earth rich) structure through the different heat treatment steps which include hydrogen decrepitation, sintering, and annealing. The recycled magnets show similar rectangular demagnetization curves with squareness of 96 %, and only a slightly decreased remanence of 5 % to 1.31 T, but a larger decrease in coercivity of 21 % to 1703 kA/m. A new GBD step using 1.5 wt.% Tb with a pure Tb-foil as diffusion source leads again to the formation of a core-shell structure with 0.5 µm thick Tb-shells which is similar to the microstructure of the original magnets prior to recycling. The coercivity of the recycled magnets is increased by 35 % from 1315 kA/m to 1780 kA/m at 50 °C and shows similar magnetic values as the original industrial magnets at 150 °C and 200 °C, respectively. The temperature coefficients for the remanence, α, and for the coercivity, β, can also be fully restored and even exceed the original values which leads to an improved temperature stability of the recycled magnets compared to the original magnets.

Nano to micron-size combustion particles in smokers’ homes: magnetic properties of tobacco and cigarette ashes

Cigarette emission comprises high-temperature combustion processes producing diverse harmful compounds, gases, and particulate matter that are spread through the air and can be taken by smokers and passive smokers involuntarily. We determined the magnetic properties of tobacco cigarettes from six commercial brands. We also monitored the emission of particulate matter in some smokers’ homes using low-cost sensors and the PM2.5 dataset was studied through a time series analysis. In addition, compositional, morphological, and magnetic properties of cigarette ashes were studied and compared with available data. Unexpected positive mean values of specific magnetic susceptibility (χ = 3.7 ×10-8 m3kg-1) and saturation isothermal remanent magnetization (SIRM = 0.6 ×10-3 Am2kg-1) of tobacco cigarettes indicate the presence of “magnetic condiments” in this unburned material. In contrast, as a consequence of puff and smoldering burn, a magnetic increase of up to 35-fold the reference values of unburned material evidence an important neoformation of airborne tobacco-derived magnetic particle ToMP. Mixtures of these ToMPs with different sizes, from nano to micron-sized, comprise superparamagnetic SP, single-domain SD, and multidomain MD particles. This work provides new accurate information on specific tobacco product ingredients (not declared) and the unnoticed ToMP emission after smoking habits, which are needed for tobacco products, consumers and passive smokers (including vulnerable children) exposed to second-hand smoke. ToMPs and myriad other toxicants may be inhaled, escape from the inhalation system and penetrate biological barriers leading to long-term human health risks.

Analysis of the air gap magnetic field in cylindrical magnetic couplings based on mathematical and finite element approach

The air gap magnetic field of a magnetic coupling plays a crucial role in the examination of its static torque and eddy current losses. Precise characterization of the air gap magnetic field is essential for ensuring the accuracy of performance assessments of the magnetic coupling. This study focuses on the cylindrical magnetic coupling as the subject of investigation, employing mathematical analysis and finite element methods to evaluate and quantify the magnetic field properties. The study establishes a mathematical model of the magnetic field of a magnetic coupling based on electromagnetic field principles and the superposition theorem. An analytical formula for the magnetic flux density distribution of the air-gap magnetic field is derived. Subsequently, a three-dimensional magnetic field finite element model is created using the finite element method to numerically calculate the air gap magnetic field and validate the analytical formula. The research also explores the periodic distribution characteristics of the magnetic field in the air gap, analyzing axial differences in magnetic flux density value and direction distribution influenced by end effects.

Design of superparamagnetic Fe3O4@SiO2@3,4-DABP nanocatalysts, fabrication by co-precipitation and sol-gel methods, characterization of detailed surface texture properties and investigation of solar cell performance

This research focuses on the synthesis, characterization, and evaluation of Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2@3,4-DABP magnetic nanocatalysts (MNCs) for their potential use as sensors within the intricate architectures of solar cell devices. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) surface area measurements were carried out to characterize the structural, morphological and magnetic properties of the MNCs. The MNCs exhibit an average particle size of approximately 10 nm. Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2@3,4-DABP MNCs have saturation magnetization values ​​of 61.64 emu/g, 37.31 emu/g, and 20.13 emu/g, respectively. Thermal analysis reveals mass change losses of 6.5%, 12% and 28.1%, respectively, indicating different thermal stability profiles. It confirms that their crystal structure is face-centered cubic spinel, with type IV hysteresis loops and H3 loops indicating a mesoporous structure according to the IUPAC classification. Efficiency tests of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@3,4-DABP MNCs in solar cell devices show efficiencies of 1.49%, 1.77% and 2.15%, respectively. As the hierarchical modification of the MNCs increases, the efficiency of the solar cell devices increases. These results highlight the potential of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@3,4-DABP as promising sensitizers in solar cell technology. Fe3O4@SiO2@3,4-DABP MNCs have high catalytic activity, chemical stability, electronic conductivity and low cost. This study also marks the first demonstration of the effectiveness of environmentally friendly Fe3O4@SiO2@3,4-DABP MNCs in enhancing solar cell performance, prepared via a cost-effective, simple and eco-friendly approach.

Evolution of metallicity, enhancement of [formula omitted] and magnetic anisotropy energy in Y[formula omitted]NiIrO[formula omitted]: Hydrostatic ([111]) strain influence

Ir-based double perovskite oxides (DPO) provide a distinct electronic and magnetic behavior due to entanglement among lattice distortion, strong electron correlation, and spin–orbit coupling (SOC). In this work, we investigated the hydrostatic ([111]) strain impact on the physical properties of the Y2NiIrO6 DPO using ab-initio calculations. Unstrained motif displayed the ferrimagnetic (FiM) spin state owing to strong antiferromagnetic (AFM) interactions between Ni↑ and Ir↓ ions, further confirmed by the computed partial spin magnetic moments and 3D spin-magnetization density iso-surfaces plots. A Mott-insulating state is established with an energy band gap (Eg) of 0.43 eV due to the existence of a rare Ir+4 state having Jeff.=12 and a Curie temperature (TC) of 198 K using the Heisenberg Hamiltonian model, which is up to the experimental observations. The easy magnetic axis is the [010] (b-axis) having a giant magnetic anisotropy energy (MAE) constant of 1.7 × 108 erg/cm3. Moreover, it is predicted that strain holds the FiM spin order as a magnetic ground state for the considered range of ±8%. Notably, an electronic transition from Mott-insulating to a metallic state is established at a critical compressive strain of −8%, where the admixture of Ir 5d states appears at/around the Fermi level. On the other hand, Eg solely increases with the increase of tensile strain amplitude. Due to strong and weak hybridization, the spin/orbital magnetic moment value is reduced and enhanced as a function of compressive and tensile strains, respectively. Along with this, it is found that MAE/TC increases to 25%/18% and 15%/10% at −8% compressive and ＋8% tensile strains due to larger structural distortion than that of the unstrained one, which enhances the system potential for magnetic memory devices.

A 3D shell model for static and free vibration analysis of multilayered magneto-elastic structures

In this paper, an exact 3D coupled magneto-elastic shell model for static and free vibration analysis of multilayered piezomagnetic smart structures is presented. The introduction of the mixed curvilinear orthogonal reference system (α,β,z) allows investigations of plates, cylindrical shells, cylinders and spherical shells as actuators or sensors and also in free vibration conditions. The present exact 3D coupled shell model is composed of four second-order differential equations whose primary variables are the three displacements u, v and w and the magnetic potential ψ. Displacements, stresses, strains, magnetic potential, magnetic induction and circular frequency values are computed to understand the behaviour of piezomagnetic smart structures. The resolution method adopted for the present 3D magneto-elastic problem is based on harmonic forms in α and β in-plane directions and the exponential matrix method in the z direction. Simply supported one-layered/multilayered structures with 0° or 90° orthotropic angles have been analysed. The results section is divided into a first part related to the validation of the proposed 3D model and a second part where new benchmark cases are presented and discussed. Different lamination schemes, load boundary conditions, geometries and materials are studied. Magneto-elastic coupling, thickness and material layer effects are discussed for thin and thick structures. The main novelty of the present exact 3D coupled magneto-elastic shell model stands in the ability to analyse several geometries and multilayered configurations embedding piezomagnetic materials under the action of different boundary loads via a general mathematical formulation.

Migratory birds can extract positional information from magnetic inclination and magnetic declination alone.

Migratory birds are able to navigate over great distances with remarkable accuracy. The mechanism they use to achieve this feat is thought to involve two distinct steps: locating their position (the 'map') and heading towards the direction determined (the 'compass'). For decades, this map-and-compass concept has shaped our perception of navigation in animals, although the nature of the map remains debated. However, some recent studies suggest the involvement of the Earth's magnetic field in the map step. Here, we tested whether migratory songbirds, Eurasian reed warblers (Acrocephalus scirpaceus), can determine their position based on two magnetic field components that are also associated with direction finding, i.e. magnetic inclination and magnetic declination. During a virtual magnetic displacement experiment, the birds were exposed to altered magnetic inclination and magnetic declination values that would indicate a displacement from their natural migratory corridor, but the total intensity of the field remained unchanged, creating a spatial mismatch between these components. The response was a change in the birds' migratory direction consistent with a compensatory re-orientation. This suggests that birds can extract positional as well as directional information from these cues, even when they are in conflict with another component of the magnetic field. It remains to be seen whether birds use the total intensity of Earth's magnetic field for navigation.

Development of the magnetodielectric properties of BaTiO3-CoFe2O4 multiferroic composites

The lead-free x CoFe2O4 – (1-x) BaTiO3 (x= 0, 0.075, 0.15, 0.225, and 1) composites have been prepared via the solid-state process. The composites' microstructure, dielectric, ferroelectric, ferromagnetic, and magnetodielectric (MD) properties were investigated. Notably, XRD analysis indicates a decrease in the tetragonality factor (cT/aT) of the BTO phase, accompanied by an expansion of the unit cell as x increases from 7.5 to 22.5 wt.%. According to the FESEM images, the CoFe2O4 (CFO) grains are uniformly distributed in the matrix with the formation of no impurity phase. The optimal dielectric properties (dielectric constant (εr) ∼ 2018 and dielectric loss factor (tan δ) ∼ 0.16) and ferroelectric characteristics (saturation polarization (PS) ∼ 12 μC/cm2 and remnant polarization (Pr) ∼ 10 μC/cm2) are achieved at x=7.5 wt.%, attributed to the minimal presence of the non-ferroelectric CFO phase. By increasing the ferrite content (up to 22.5 wt.%), the ferroelectric properties of the samples showed a gradual diminution. Also, from x=7.5 to 22.5 wt.%, a sharp increase in the saturation magnetization (from 3.75 to 11.3 emu/g) and remnant magnetization (from 0.93 to 2.35 emu/g) values was observed, while the coercivity diminished from 475.8 to ∼ 272 Oe. The simultaneous observation of two ferroic characteristic hysteresis loops validated the multiferroicity of the composites (x=7.5, 15, and 22.5 wt.%). The maximum MD constant (4.68%) was measured for x=22.5 wt.% composite at the applied magnetic field of 7 kOe.

The Identification of Faults using Magnetic Method in Kulonprogo, Yogyakarta, Indonesia

The aims of this study to identify faults and identify subsurface lithology using magnetic anomaly data in the Kulonprogo. In the acquisition was carried out using a Proton Procession Magnetometer (PPM) Geotron G5 with 62 measurement points and a distance of ±1 km between point. Measurements were made on Kebobutak (Tmok), Aluvium (Qa), Andesit (a), and Sentolo (Tmps) formations. The total magnetic field data processing is done with several correction, namely diurnal correction, IGRF, reduce to equator, upward continuation at an altitude of 2000 m, and reduce to pole, and 2D modelling using the forward modelling method. The result of the analysis obtained magnetic field anomaly values in the range of values -400 to 950 nT. The 2D modelling shows that the research area is composed of 4 dominating rock types, namely andesite rock with a susceptibility value of 94 x 10-3, andesite breccia rock with a susceptibility value of 29 x 10-3, clay rock with a susceptibility value of 0,013 x 10-3, and sandstone with a susceptibility value of 5 x 10-3. The identification result show the existence of faults line on Mount Watuaglik, Mount Kamal, and Mount Bodag.

Influence of oxygen impurities in generating ferromagnetism in GaN doped with Mn, Fe, and Cr

We report the influence of oxygen impurities in generating ferromagnetism in GaN doped with Mn, Fe, and Cr through superexchange involving Mn–O–Mn, Fe–O–Fe, and Cr–N–Cr atomic configurations. Density Functional Theory (DFT) calculations demonstrated that these configurations originate within VGa-ON\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${V}_{\ ext{Ga}}-{O}_{\ ext{N}}$$\\end{document} complex defects by incorporating Mn2+, Fe2+, and Cr3+ ions into gallium vacancies (VGa\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${V}_{\ ext{Ga}}$$\\end{document}) sites promoted by the presence of oxygen as a substitutional impurity (ON\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${O}_{\ ext{N}}$$\\end{document}). These co-doped GaN microstructures were synthesized using the thermal evaporation method. Cathodoluminescence (CL) and photoluminescence (PL) measurements confirmed the presence of VGa-ON\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${V}_{\ ext{Ga}}-{O}_{\ ext{N}}$$\\end{document} complex defects in all GaN-grown samples. X-ray photoelectron spectroscopy (XPS) measurements confirmed the successful incorporation of Mn2+, Fe2+, and Cr3+ ions in GaN samples. SQUID measurements demonstrated room-temperature ferromagnetism with respective saturation magnetization (Ms) and coercive field (Hc) values of ± 1.5 × 10−5 emu and 4 mT for GaN:O,Mn, ± 4.4 × 10−5 emu and 2.6 mT for GaN:O,Fe, and ± 1.7 × 10−5 emu and 2.6 mT for GaN:O,Cr.

Determination of organochlorine pesticide residues in food by polystyrene coated silica magnetic microspheres combined with gas chromatography-mass spectrometry

In this work, a sample pre-treatment technology, based on magnetite-silica-polystyrene (Fe3O4@SiO2@PS) composite as the adsorbent, combined with Gas Chromatography-Mass Spectrometry (GC–MS) has been developed and used for the trace analysis of organochlorine pesticide residues in food. SEM, TEM, FI-IR, VSM, XPS, BET, TGA and XRD techniques were used to characterize the synthetic adsorbent material, the adsorbent had excellent magnetic separation properties (saturation magnetization values with 32.7 emu g−1) and adsorption properties (adsorption capacity with 16.67 mg g−1 to 20.53 mg g−1), and the adsorption performance of Fe3O4@SiO2@PS aligned with the pseudo-second-order kinetics. Under the optimal conditions, the developed method showed satisfactory performance within a range of 0.01 to 4 mg L−1 (R2 ≥ 0.9971), the low detection limits (LOD) were from 0.05 to 0.20 μg kg−1, and the quantification limits (LOQ) were from 0.16 to 0.67 μg kg−1, respectively. The spiked recovery rates ranged from 74.7 % and 93.7 %, with relative standard deviations (RSD) from 2.09 % to 6.43 %. Thus, the developed adsorbent and method offer an efficient alternative to the commonly used SPE-based approach.

The results of a magnetic field on flow past an inclined isothermal vertical plate with heat and varying mass diffusion

This work describes the influence of a magnetic environment on the circulation of matter and thermal energy over an accelerating advanced inclined isothermal sectional surface. The temperature is elevated to . The proximity intensity is increased to . The Laplace-transform approach is applied to solve the dimensionless analytical equation. In this research work different physical variables including thermal grashof number (Tg), mass grashof number (Tm), Schmidt number (Sc), Prandtl number(Pr), time(t), velocity profile ( ), temperature ( ), and intensity ( ) are investigated. The output of the graph produced by the Matlab software commands an energy equation, momentum equation, and concentration equation. The values are shown in an aligned pattern for a variety of flow variables. Diagrammatic representations of the fluid velocity profiles are provided. The velocity rises corresponding to different Tg and the velocity rises corresponding to different Tm. As the angle is decreased, the velocity increases differently. , As the different magnetic environment values lower, the velocity rises. Elevated values of angle ( ), Sc, Pr, and contribute to an enhancement in local skin friction, and an upsurge in Gr, Gc, and t leads to a reduction. A tabulated presentation of Nusselt quantities reveals a positive correlation with increasing Pr. Similarly, Sherwood quantities, as tabulated for various parameters, demonstrate a proportional increase with rising Sc.

Effect of Thermal Processing on the Structural and Magnetic Properties of Epitaxial Co2FeGe Films.

The structure and magnetic properties of epitaxial Heusler alloy films (Co2FeGe) deposited on MgO (100) substrates were investigated. Films of 60 nm thickness were prepared by magnetron co-sputtering at different substrate temperatures (TS), and those deposited at room temperature were later annealed at various temperatures (Ta). X-ray diffraction confirmed (001) [110] Co2FeGe || (001) [100] MgO epitaxial growth. A slight tetragonal distortion of the film cubic structure was found in all samples due to the tensile stress induced by the mismatch of the lattice parameters between Co2FeGe and the substrate. Improved quality of epitaxy and the formation of an atomically ordered L21 structure were observed for films processed at elevated temperatures. The values of magnetization increased with increasing TS and Ta. Ferromagnetic resonance (FMR) studies revealed 45° in-plane rotation of the easy anisotropy axis direction depending on the degree of the tetragonal distortion. The film annealed at Ta = 573 K possesses the minimal FMR linewidth and magnetic damping, while both these parameters increase for another TS and Ta. Overall, this study underscores the crucial role of thermal treatment in optimizing the magnetic properties of Co2FeGe films for potential spintronic and magnonic applications.

Inside Ceramics and Between MgO Grains: Solid-State Synthesis of Intergranular Semiconducting or Magnetic Spinels.

Configurations of composite metal oxide nanoparticles are typically far off their thermodynamic equilibrium state. As such they represent a versatile but so far overlooked source material for the intergranular solid-state chemistry inside ceramics. Here, it is demonstrated how the admixture of Fe3+ and In3+ ions to MgO nanoparticles, as achieved by flame spray pyrolysis, can be used to engage ion exsolution, phase separation, and subsequent spinel formation inside the network of diamagnetic and insulating MgO grains. Extremely high uniformity in the distribution of intergranular ferrimagnetic MgFe2O4 films and grains with resulting magnetic coercivity values that depend on the nanoparticles' initial Fe3+ concentration is achieved. Moreover, percolating networks of semiconducting MgIn2O4 are derived from MgO nanoparticles with admixtures of 20 at% In3+ that gives rise to an enhancement of dc conductivity values by more than five orders of magnitude in comparison to the insulating MgO host. The here presented approach is general and applicable to the synthesis of a variety of functional spinel nanostructures embedded inside ceramic matrices. Nanoparticle loading with aliovalent impurity ions, the level of nanoparticle powder density after compaction, and sintering temperature are key parameters for this novel type of solid-state chemistry in between the host grains.

Nanostructured spinel ferrites: A comprehensive study on the synthesis, characterization, and magnetic properties of Zn and Mn substituted magnetite nanoparticles produced through the co-precipitation method

Seven cubic spinel ferrite nanoparticles were successfully synthesized through the co-precipitation method. These nanoparticles include Fe3O4, Zn0.4Fe0.62+Fe23+O4, Mn0.4Fe0.62+Fe23+O4, Zn0.6Mn0.4Fe0.42+Fe1.63+O4, Zn0.4Mn0.6Fe0.42+Fe1.63+O4, Zn0.4Mn0.4Fe0.22+Fe23+O4, and Zn0.4Mn0.4Fe0.42+Fe1.83+O4. The Rietveld method was used to analyze X-ray diffraction data, confirming that all samples have a single-phase cubic spinel structure. The presence of zinc and manganese ions in magnetite lattice leads to changes in lattice parameters and crystallite size, resulting in a range of 7–12 nm crystallite sizes. Fourier transform infrared spectroscopy (FT-IR) analysis of nanoparticles reveals two significant adsorption peaks at 560-576 cm−1 and 437-449 cm−1, corresponding to metal ion stretching vibrations at tetrahedral and octahedral sites. The X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of iron, zinc, and manganese in various oxidation states. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images showed spherical, agglomerated nanoparticles. The study confirmed the elemental composition and mapping images of prepared samples using energy-dispersive X-ray spectroscopy (EDS). The magnetic properties of the synthesized nanoparticles were meticulously examined utilizing a vibrating sample magnetometer (VSM) at room temperature. A direct correlation is established between the structural alterations induced by Zn2+/Mn2+ and their subsequent effects on magnetic characteristics, specifically through the reallocation of cations and the mechanisms of electron hopping occurring at the B-sites. The structural modifications result in enhanced superparamagnetic behavior, exhibiting saturation magnetization values between 46.01 and 69.38 emu/g. The sustainable characteristics of these materials render them highly viable options for applications in environmental remediation and green technology.

Nanostructured Coatings of 3d-Metals Produced by Green Chemistry Methods: Analysis of Inhomogeneities by Static and Dynamic Magnetic Methods

The study investigates carbon-containing coatings of 3d-metals (Ni, Co, Fe) produced by chemical deposition method using arabinogalactan. The coatings were analyzed using X-ray diffraction, FMR, and M(H) magnetometry. Measurement of M(H) in plane and perpendicular to the plane of the magnetic coatings allowed determining the distribution of demagnetizing factor in the studied coatings. The obtained distributions of the demagnetizing factor were used to analyze the angular dependences of the ferromagnetic resonance field. The values of magnetization and perpendicular anisotropy field were estimated. The paper illustrates the effect of texture on the magnetic parameters.