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We present computational results on electronic, magnetic, and structural properties of CoVMnSb, a quaternary Heusler alloy. Our calculations indicate that this material may crystallize in two energetically close structural phases: inverted and regular cubic. The inverted cubic phase is the ground state, with ferrimagnetic alignment, and around 80% spin polarization. Despite having a relatively large bandgap in the minority-spin channel close to the Fermi level, this phase does not undergo a half-metallic transition under pressure. This is explained by the "pinning" of the Fermi level at the minority-spin states at the Γ point. At the same time, the regular cubic phase is half-metallic and retains its perfect spin polarization under a wide range of mechanical strain. Transition to a regular cubic phase may be attained by applying uniform pressure (but not biaxial strain). In practice, this pressure may be realized by an atomic substitution of non-magnetic atoms (Sb) with another non-magnetic atom (Si) of a smaller radius. Our calculations indicate that 25% substitution of Sb with Si results in a half-metallic regular cubic phase being the ground state. In addition, CoVMnSb0.5Si0.5 retains its half-metallic properties under a considerable range of mechanical pressure, as well as exhibits thermodynamic stability, thus making this alloy attractive for potential spintronic applications. We hope that the presented results will stimulate experimental efforts to synthesize this compound. [ABSTRACT FROM AUTHOR]

In this work, we shed light on the mechanism behind the complexity of the anomalous Hall effect (AHE) in the rare earth-transition metal (RE-TM) compound. To achieve a comprehensive picture, we first theoretically investigate the pure elemental metals and observe that the AHE of RE Gd is negative while that of TM Co is positive. We then investigate magnetic properties and AHE behavior for two typical cases of TM-rich and RE-rich compositions that correspond to GdCo5 and GdCo3 alloys, respectively. The observation that net magnetization is not a decisive factor in assessing the AHE value is consistent with recent claims. Besides, our investigations reveal a significant role of the Gd sublattice to the AHE. The reduction AHE signal under a high-applied field is attributed to the counteraction between the positive and negative AHC contributions when the TM and RE sub-moments are aligned parallel. On a bright note, our new findings can be successfully employed to unravel two types of aberrant humps of AHE signals near compensation temperature. [ABSTRACT FROM AUTHOR]

It is established that 2D magnetic materials are the ideal platform for building up modern-day electronic and spintronic devices. The popular ways to achieve 2D magnetic materials are mechanical exfoliation and chemical vapor deposition. However, the direct chemical synthesis route of such magnetic 2D materials on a large scale is relatively unexplored. This article reports an easy and cost-effective facile chemical synthesis with a proper capping agent and magnetic study of free-standing 2D Cr2S3 nanosheets and Cr2S3 nanoparticles within the temperature range of 2–300 K under the magnetic field of up to 5 T. Although few magnetic results on 2D Cr2S3 are available in the literature, there is enough scope to work for an in-depth understanding of the magnetic aspects of this 2D material. Here, ferrimagnetic ordering with a sufficiently high coercivity of up to 0.139 T at 2 K along with a tendency to the saturation in magnetization down to a certain temperature limit is observed. Contrary to the strong antiferromagnetic coupling with a Néel temperature, as observed by previous researchers, is also observed for this chemically synthesized 2D Cr2S3 nanosheets. A transition temperature of 117 K is observed for the Cr2S3 nanosheets, whereas for Cr2S3 nanoparticles, a transition temperature of 101.7 K is observed with negligible coercivity. This facile synthesis technique may be applied to achieve other non-van der Waals type 2D magnetic materials. These kinds of non-van der Waals type 2D magnets will be useful to modern-day spintronic devices. [ABSTRACT FROM AUTHOR]

Fully compensated ferrimagnetic half metals have attracted great attention in spintronics. Unlike many previous calculations based on hypothetical ordered alloys, here we look for existing solid solution series taking as an example Co1−xCrxS2. Calculations find that a low-spin state for Cr that matches early experiments and a fully compensated ferrimagnetic half metal with Curie temperature above room temperature is found at x ≈ 0.33. Our study demonstrates the method of combining two half metals with light and heavy 3d metals in a solid solution to achieve compensation, where atomic disorder does not destroy the desired properties. [ABSTRACT FROM AUTHOR]

Recently, we [J. Magn. Magn. Mater. 514 (2020) 167242] presented a study of the dynamic magnetic loop features of molecular-based magnetic materials and ferrimagnetism that were investigated by using a mixed spin 1/2 and spin-1 ferrimagnetic Ising system within the path probability method. We found several interesting dynamic magnetic hysteresis properties and observed that the obtained results are in qualitatively good agreement with some theoretical and experimental studies in magnetic materials. We extended our recent previous published work to study the dynamic magnetic hysteresis properties of molecular-based magnetic materials and ferrimagnetism utilizing the mixed spin (2, 5/2) ferrimagnetic Ising system on a hexagonal lattice employing the path probability method. The spin (2, 5/2) Ising system is one of the most suitable and most used prototypical systems to investigate many molecular-based magnetic materials and ferrimagnetic materials. We found more interesting dynamic magnetic hysteresis properties such as double, triple, quadruple and quintuple loop behaviors for the layer magnetization, and only double and triple loops for the total magnetization. We found that some of our obtained results are in qualitatively good agreement with some theoretical, experimental reported works, and the works on some magnetic materials as obtained by the melt-spinning technique. [ABSTRACT FROM AUTHOR]

Yttrium Iron Garnet (YIG) ferrites, characterized by their superior magnetic and dielectric attributes, are instrumental in advancing the development of microwave devices, particularly in enhancing high-frequency performance, integration, and miniaturization. This paper synthesizes YIG ferrite materials with the composition Bi 0.6 Y 1.4-x Ca 1+x Fe 4.5-x V 0.5 Ge x O 12 (x = 0.10 to 0.50, incrementing by 0.10) through the solid-state sintering method. It delves deeply into the mechanism by which Ca2+-Ge4+ ions substitution regulates the magnetic properties of BiV-YIG. The microstructural and magnetic properties of the samples were systematically tested and analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometry (VSM), and TE106 perturbation method. At a substitution content of x = 0.50, the substitution of Ge4+ ions for the Fe3+ ions at the d-site transforms the material from ferrimagnetic to paramagnetic, and the saturation magnetization of the sample drops to 132.74 G. By calculating the ferromagnetic resonance (FMR) linewidth using the law of approach to saturation, the study elucidates the negative impact of low saturation magnetization on FMR linewidth. The mechanisms proposed in this paper provide theoretical and experimental bases for reducing the FMR linewidth of high dielectric constant Bi-substituted YIG, paving the way for developing high-dielectric, low-loss YIG ferrite materials for microwave devices. [ABSTRACT FROM AUTHOR]

In this paper, the compensation characteristics and hysteresis loops of a ferrimagnetic mixed-spin diluted fullerene-like (XY)540 are studied based on Monte Carlo method. We show the ground-state phase diagrams in order to explore the stable configuration states. The temperature dependence of magnetization, magnetic susceptibility, internal energy, specific heat, and entropy are presented. The phase diagram including compensation temperature Tcomp and phase change temperature Tc is obtained. The multi-loop hysteresis phenomena under the influence of diverse physical parameters are observed. Finally, the critical exponents of the fullerene-like (XY)540 are obtained. [ABSTRACT FROM AUTHOR]

Perpendicularly magnetized Co-based Heusler alloys are promising candidates in high-performance spintronic devices. However, there is a contradiction between thermal stability and damping-like spin–orbit torque (SOT) efficiency in Co-based Heusler alloys with interface-induced perpendicular magnetic anisotropy (PMA). Here, we present epitaxially grown perpendicularly magnetized Mn1+xCo2−xAl (MCA) Heusler alloys through tetragonal distortion. Ferrimagnetism and distortion-induced PMA are obtained in MCA Heusler alloys. A large effective spin Hall angle (θeff) up to 0.33 is experimentally demonstrated in Pt/MCA bilayers, markedly surpassing that in conventional Pt/FM bilayers. Consequently, SOT-induced efficient magnetization switching is realized in Pt/MCA bilayers, with a critical switching current density (Jc) as low as 4 × 107 A/cm2. The large θeff and high SOT efficiency would be attributed to the staggered magnetic exchange torques in the ferrimagnetic MCA Heusler alloys. These findings demonstrate that perpendicularly magnetized ferrimagnetic MCA Heusler alloys are highly promising for high-density SOT-magnetic random-access memory with superior thermal stability and low power consumption. [ABSTRACT FROM AUTHOR]

NiCr2O4 nanoparticles with average particle size ∼15 nm, a single-domain size maintains the bulk canted antiferromagnetic ground state, were synthesized by a microwave combustion method. The magnetic behavior was carefully investigated by static and dynamic magnetic susceptibility measurements. In addition to a spin-glass-like behavior below paramagnetic-ferrimagnetic transition at T C, the NiCr2O4 nanoparticles demonstrate a low-temperature cluster spin glass transition below the spin canting transition T S, which manifests itself as a magnetic anomaly peak around ∼12 K (at 100 Oe) in the zero-field cooled magnetization with a relatively stronger field dependence in a 'de Almeida-Thouless' line for spin glasses. The AC susceptibility analyses in different approaches demonstrate a larger relative peak temperature variation per frequency decade and a longer characteristic relaxation time in the order of 0.04 and 10−7 s, against 0.01 and 10−9 s for the high-temperature blocking, indicating the slow spin dynamics for the low-temperature cluster glassy phase. A field-temperature magnetic phase diagram is proposed for the single-domain NiCr2O4 nanoparticles. [ABSTRACT FROM AUTHOR]

We prepared ultrafine MnCo 2 O 4 particles using a facile sol–gel autocombustion method. The structural and vibrational characterizations confirmed the formation of a pure cubic spinel phase in as-synthesized MnCo 2 O 4 particles. The surface morphology analyses revealed the porous structure with an average particle size of 5 nm and uniform distribution of manganese (Mn), cobalt (Co), and oxygen (O) in the particles. We observed the presence of multiple valence states of Mn and Co, occupying both tetrahedral and octahedral sites, enhancing our insight into the material's electronic properties and structural configuration. Our magnetization studies unveiled a Curie Temperature (T C) of 185 K with ferrimagnetic ordering below T C , resulting in substantial magnetization (9.8 emu/g) and coercivity (3.46 kOe) at 2 K and weak magnetic behavior above T C. This is attributed to the finite size and surface effects. Furthermore, the incorporation of MnCo 2 O 4 nanoparticles and graphene oxide into a polyurethane foam matrix resulted in an excellent sound absorption coefficient of 90 % at 2000 Hz. This outstanding acoustic performance underscores the versatile applications of MnCo 2 O 4 nanoparticles in diverse noise mitigation applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the ion-exchange technique in molten salts was investigated to introduce copper ions in a bioactive and ferrimagnetic devitrified glass. This approach aimed to develop a magnetic and bioactive material for oncologic bone implants, able to join the ability to promote bone bonding to hyperthermic therapy while simultaneously lowering the risk of developing post-surgery infections. The ion-exchange approach was developed in order to overcome experimental critical issues related to the influence of copper introduction as a starting reagent, during the material synthesis, on magnetite nucleation. The magnetic devitrified glass was prepared by melt and quenching route, followed by ion exchange in a mixture of molten sodium and copper nitrates, in three different Na/Cu molar ratios (20, 200, 2000). The obtained samples were analysed in terms of morphology, composition, ability to release heat, bioactivity and antibacterial properties. The results revealed that copper ion-exchange involved both sodium and calcium ions and the precipitation of few amounts of copper oxide aggregates occurred. The crystalline nature of the starting material and its ability to reach the temperature needed for hyperthermia, under exposition to an alternating magnetic field, were not affected. A bacteriostatic effect was obtained by samples with the highest copper amount and the copper doping did not affect the bioactivity of the glass ceramic. [ABSTRACT FROM AUTHOR]

Ferrimagnetic Mn0.25Co0.75Fe2O4 (MCF) nanoparticles were synthesized via sol–gel autocombustion method. Polyaniline (PANI) and PANI nanocomposites with MCF as filler (PANI/MCF) were synthesized through chemical oxidative in-situ polymerization of aniline under the presence of varying weight percentage of the MCF (10%, 20% and 50%). The MCF, PANI and PANI/MCF nanocomposites were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analyzer (TGA), field emission scanning electron microscopy equipped with elemental detection (FESEM-EDAX) and vibrating sample magnetometer. The XRD and FTIR spectra confirmed the formation of pure phase with high crystallinity for all the samples. TGA study showed the increased thermal stability of PANI with addition of MCF. MCF and PANI/MCF nanocomposites showed ferrimagnetic hysteresis loop under external magnetic field at room temperature. Additionally, the ac conductivity, dielectric and electrical properties as a function of frequency ranging from 100 Hz to 120 MHz, were investigated for all the samples using impedance analyzer at room temperature. Dielectric, TGA and magnetic studies showed that PANI/MCF with 50 weight percentage of MCF has maximum ac conductivity, thermal stability and moderate magnetic properties. Hence, it could be a potential candidate to be used as dielectric material in high frequency capacitors and for electromagnetic interference shielding material at high frequency. [ABSTRACT FROM AUTHOR]

The exchange integral in the magnetic response of a spherical metallic iron (Fe) and nickel (Ni) nanoparticle is theoretically studied by using Monte Carlo simulations. To this end, using the nanoparticles model in spherical coordinates, we compute magnetization, magnetic susceptibility, specific heat, internal energy, and hysteresis loop over a wide range of temperatures for an Fe and Ni nanoparticle with a size of about 2 nm. The phase transition temperatures are interpolated versus the exchange parameters, and it is observed that the dependence on the coupling parameter is completely linear. Moreover, from the susceptibility results of the samples, the sharpest peak with the least fluctuation gives us the most appropriate Curie temperature and exchange integral for this system. However, the peak related to the heat capacity is also in the Curie temperature range. From the internal energy results, it can be understood that with the increase in phase transition and interaction, the system reaches equilibrium. The magnetic coercive field and remanent magnetization caused by nanoparticles indicate superparamagnetic properties at room temperature. At the end, the obtained results allow us to theoretically determine the magnetic properties of spherical nanoparticles and pave the way for the development of nanoparticles for many applications. [ABSTRACT FROM AUTHOR]

The anomalous Nernst effect (ANE) has garnered significant interest for practical applications, particularly in energy harvesting and heat flux sensing. For these applications, it is crucial for the module to operate without an external magnetic field, necessitating a combination of a large ANE and a substantial coercive force. However, most materials exhibiting a large ANE typically have a relatively small coercive force. In our research, we have explored the ANE in amorphous ferrimagnetic TbCo alloy films, noting that the coercive force peaks at the magnetization compensation point (MCP). We observed that transverse Seebeck coefficients are amplified with Tb doping, reaching more than 1.0 μV/K over a wide composition range near the MCP, which is three times greater than that of pure Co. Our findings indicate that this enhancement is primarily due to direct conversion, a product of the transverse thermoelectric component and electrical resistivity. TbCo films present several significant advantages for practical use: a large ANE, the capability to exhibit both positive and negative ANE, the flexibility to be deposited on any substrate due to their amorphous nature, a low thermal conductivity, and a large coercive force. These attributes make TbCo films a promising material for advancing ANE-based technologies. [ABSTRACT FROM AUTHOR]

The high temperature compression experiments of 2209 duplex stainless steel were carried out by using Glee-ble3800 thermal simulator, the rate was 0,01~10 s-1, and the deformation temperature was 950~1 100°C. The strain rate and deformation temperature were analyzed and the effect of strain rate and deformation temperature were analyzed. The high-temperature rheological behavior of 2209 duplex stainless steel was investigated, and the effects of strain rate and deformation temperature on the two-phase relationship of 2209 duplex stainless steel were analyzed, the strain rate compensation factor Z was introduced, and the Arrhenius eigenmodel equation was established. The results show that the theoretical value of peak stress calculated numerically by this constitutive model fits well with the experimental results, and the correlation is 97,3 %, which verifies the feasibility of the model. [ABSTRACT FROM AUTHOR]

There is a growing interest in BiFeO3-based alloys because of the possibility it offers for developing high-temperature high-performance piezoelectric materials and for their interesting multiferroic properties. Often such ceramics are synthesized with additives either to reduce/suppress leakage current that the system inherits from the parent compound BiFeO3 or to promote sintering via formation of the liquid phase. We demonstrate here the propensity for stabilizing ferromagnetism in the ferroelectric solid solution BiFeO3–PbTiO3 (BF–PT) when synthesized with additive MnO2. Detailed investigation revealed that the ferromagnetic property of the ceramic is extrinsic and caused by the additive enabled precipitation of trace amount of the ferrimagnetic Pb-hexaferrite phase, not easily detected in conventional x-ray diffraction measurements. We also show that the ferromagnetic property is induced in Co-modified BF–PT. However, in this case, the additive stabilizes the CoFe2O4 spinel ferrite phase. While our findings offer a strategy to develop particulate magnetoelectric multiferroic composites using additive assisted precipitation of the ferrimagnetic phase(s) in BiFeO3-based ferroelectric alloys, it also helps in better understanding of the electromechanical response in BFO-based alloys. [ABSTRACT FROM AUTHOR]

In our studies, we combined two powdered materials, i.e., ferroelectric triglycine sulfate (TGS) and ferrimagnetic magnetite Fe3O4, to obtain a magnetoelectric composite. The ferroelectric (E) part, i.e., TGS, was a hybrid organic–inorganic crystal, which we obtained as a pure single crystal from an aqueous solution using a static water evaporation method. The magnetic (M) part of the composite was commercially available magnetite. The samples used for the dielectric and magnetoelectric measurements were cold-pressed and made in the form of a circular tablet. The measuring electrodes were made of silver-based conductive paste and were attached to the sample. We measured the temperature dependencies of selected electrical parameters (e.g., dielectric permittivity, electrical capacity, and loss angle tangent). We used the dynamic lock-in method to check whether magnetoelectric coupling existed between the E and M phases. In this paper, we present the dielectric properties of pure monocrystalline TGS as a reference sample and compare the results for TGS powder, TGS + carbon powder, and TGS + Fe3O4 powder. The magnetoelectric coupling presumably appeared for the composite TGS + 10 wt. % Fe3O4, as evidenced by the shift in the phase transition temperature in the TGS. Moreover, the theoretical interpretation of the effect is proposed. [ABSTRACT FROM AUTHOR]

Orbital currents play a fundamental role in a wide range of transport phenomena. Recently, the discovery of a novel chiral orbital current state in the ferrimagnetic nodal-line semiconductor Mn3Si2Te6 has attracted significant interest, supported by anomalous I–V characteristics and time-dependent bistable switching. However, the direct experimental verifications, combining electrical transport and magnetic measurement, that detect the variation of the magnetic properties vs the current are still rare. Here, we investigate the transport properties of Mn3Si2Te6 and track the current-induced dynamics of the magnetic moment. Reflective magnetic circular dichroism reveals that significant alterations in Mn3Si2Te6 magnetoresistance in response to an electric field are necessarily coupled with a magnetic phase transition, establishing a rare correlation. Our findings indicate the predominance of magnetic chiral orbital currents in the colossal angular magnetoresistance effect, offering a unique platform for advanced studies in orbital magnetism. [ABSTRACT FROM AUTHOR]

Polycrystalline [(0.5) Bi0.5Na0.5TiO3-(0.5) LaFeO3] multiferroic composite is prepared by using the solid-state reaction method. The crystal structure of both phases is characterized by using the X-ray diffraction method (XRD) and confirms the presence of rhombohedral (i.e., bismuth sodium titanate) and orthorhombic (i.e., lanthanum ferrite) phases in the composite. The microstructure of the composite is analyzed using field emission scanning electron microscopy (FESEM). The crystal structure is further studied with Raman spectroscopy. The present composite exhibits ferroelectric and ferrimagnetic-like properties, revealing its multiferroic behavior. Furthermore, the impedance analysis of the composite shows the negative temperature coefficient of resistance behavior. The present study describes the structural and physical properties of the possible lead-free multiferroic composite. [ABSTRACT FROM AUTHOR]

The magnetic anisotropy of strontium ferrite (SF)/PA12 filament, a popular hard magnetic ferrimagnetic composites that is used for 3D-printing of permanent magnets, is studied by vibrating sample magnetometry. The studied filaments have a composition of SF/PA-12 thermoplastic composite with a 40% wt. ratio of SF. SF particles are non-spherical platelets with an average diameter of 1.3 um and a diameter to thickness ratio of 3. Filaments are produced by a twin-screw extruder and have a diameter of 1.5 mm. SEM images show that the SF particles are homogeneously distributed through the filament. VSM measurements on different parts of the filaments show that the outer part of the cylindrical filament has a higher anisotropy, and the core is mostly isotropic. This conclusion is consistent with computational work by others which suggest that particle alignment predominantly takes place near the walls of the extruder die where shear flow is maximum. Additional hysteresis curve measurement of the outer cylindrical part of the filament parallel to the r and ϕ directions indicates that the squareness of the hysteresis curve (S) is larger in the r-direction. This indicates that the outer surface of the filament has a strong easy axis in the r-direction. We conclude that the SF platelets line up parallel to the walls of the extrusion die. [ABSTRACT FROM AUTHOR]

The accelerating use of organic dyes in various industries has led to a surge in water pollution, especially from non-biodegradable dye effluents discharged into water resources. This study addresses the critical issue of catalyzing the reduction of two prevalent dyes, methylene blue (MB) and rhodamine-B (RhB), using a multiwalled carbon nanotube-cobalt ferrite (MWCNT-CF) nanocomposite. The synthesized nanocomposite demonstrates exceptional catalytic activity, stability, and recyclability. Conventional methods for treating dye-containing wastewater often prove expensive. This study explores the efficacy of catalytic reduction, a relatively fast process facilitated by semiconductor nanoparticles. Structural analyses using X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) confirm the formation of the nanocomposite, revealing unsaturated surface bonds and chains conducive to adsorption. The nanocomposite exhibits a remarkable reduction in both dyes, with easy recyclability for multiple cycles. Magnetization studies confirm the ferrimagnetic nature of the nanocomposite, facilitating its efficient separation from the reaction mixture using a magnet. The study delves into the kinetics of the catalytic reduction following pseudo-first-order kinetics. The surface modifications of the nanocomposite, as revealed by TEM, contribute to enhanced adsorption and catalytic efficiency. Notably, the MWCNT-CF nanocomposite demonstrates negligible loss of catalytic activity during recycling, highlighting its potential for cost-effective and sustainable applications in dye reduction across various industries. [ABSTRACT FROM AUTHOR]

A high temperature MD effect has been observed in Pr3Fe5O12 (PrIG) which is a new member of rare earth iron garnets (RIG) family. Research indicates that this material has two dielectric relaxations in the temperature range from 370 K to 565 K and a dielectric anomaly around 580 K. The first dielectric relaxation is attributed to the conduction for the similar activation energy with conduction. The other dielectric relaxation in the higher temperature range originated from the inhomogeneous structure. And, the coupling between the ferrimagnetic phase transition and the dielectric response was observed at 1 kHz 0.35 T 580K. [ABSTRACT FROM AUTHOR]

Temperature-dependent magnetization of core-shell and alloy nanoparticles of cobalt (Co)/nickel (Ni) is investigated within the context of the classical spin Hamiltonian and Monte Carlo simulations. The results of our study indicate that the average temperature-dependent magnetization and magnetic-ordering temperature have a significant influence from variations in the core-shell ratio and chemical order in core-shell nanoparticles. Also, the alloy fraction of Co(Ni) strongly influences the magnetic ordering temperature of the nanoparticles. It is noticed that in alloy nanoparticles, the rise of the magnetic ordering temperature with the increase in Co proportion is linear. However, the same is not true for core-shell nanoparticles where the magnetic-ordering temperature deviates from the straight line fit of alloy T c . It is ascertained that core-shell Co@Ni and Ni@Co nanoparticles sustain higher temperatures in their ferromagnetic state. In the ferrimagnetic nanoparticles, there is a reduction in the saturation magnetization and a display of compensation behavior. [ABSTRACT FROM AUTHOR]

Background: Adjuvant administration of hyperthermia (HT) with radiation therapy in the treatment of cancer has been extensively studied in the past five decades. Concurrent use of the two modalities leads to both complementary and synergetic enhancements in tumor management, but presents a practical challenge. Their simultaneous administration using the same implantable thermo‐brachytherapy (TB) seed source has been established theoretically through magnetically mediated heat induction with ferromagnetic materials. Careful consideration, however, showed that regular ferromagnetic alloys lack the required conductivity to generate enough power through eddy current to overcome heat dissipation due to blood perfusion at clinically measured rates. Purpose: We characterized the TB implant that combines a sealed radioactive source with a ferrimagnetic ceramic (ferrite) core, serving as a self‐regulating HT source when placed in an alternating electromagnetic field. To increase the heat production and uniformity of temperature distribution the empty spacers between radioisotope seeds were replaced by hyperthermia‐only (HT‐only) seeds. Methods: The heat generation due to eddy currents circulating in the seed's thin metal shell, surrounding the core, depends drastically on the core permeability. We identified a soft ferrite material (MnZnFe2O4$\rm MnZnFe_2O_4$) as the best candidate for the core, owing to its high permeability, the HT‐range Curie temperature, adjustable through material composition, and a sharp Curie transition, leading to heat self‐regulation, with no invasive thermometry required. The core permeability as a function of temperature was calculated based on measured resistor‐inductor (RL) circuit parameters and material B‐H curves. The thickness of the shell was optimized separately for TB and HT‐only seeds, having slightly different dimensions. Heat generation was calculated using the power versus temperature approximation. Finally, the temperature distribution for a realistic prostate LDR brachytherapy plan was modeled with COMSOL Multiphysics for a set of blood perfusion rates found in the literature. Results: The small size of the investigated ferrite core samples resulted in demagnetization significantly decreasing the relative permeability from its intrinsic value of ∼5000 to about 11 in the range of magnetic field amplitude and frequency values relevant to HT. The power generated by the seed dropped sharply as the shell thickness deviated from the optimal value. The optimized TB and HT‐only seeds generated 45 and 267 mW power, respectively, providing a HT source sufficient for >90% volume coverage even for the highest blood perfusion rates. The toxicity of the surrounding normal tissues was minimal due to the rapid temperature fall off within a few millimeters distance from a seed. Conclusions: The investigated TB and HT‐only seed prototypes were shown to provide sufficient power for the concurrent administration of radiation and HT. In addition to being used as a source for both radiation and heat at the onset of cancer therapy, these implanted seeds would be available for treatment intensification in the setting of salvage brachytherapy for locally radiorecurrent disease, possibly as a sensitizer to systemic therapies or as a modulator of the immune response, without another invasive procedure. Experimentally determined parameters of the ferrite material cores provided in this study establish a mechanistic foundation for future pre‐clinical and clinical validation studies. [ABSTRACT FROM AUTHOR]

Half‐metallic ferromagnets (HMFs) are highly desirable materials for applications in spintronics because of their semiconducting behavior for one spin projection and metallic nature for the other. To operate spintronic devices at room temperature (RT), HMFs should simultaneously have a large saturation magnetization (MS), high magnetic Curie temperature (TC), and a wide half‐metallic gap. However, HMFs that simultaneously fulfill these three criteria are rare. In this work, we report for the first time on the ferrimagnetic double perovskite oxides of Sr2CrHfO6 (SCHO) with a magnetic TC up to 545 K due to the strong Cr3+(↑)Cr4+(↓) antiferromagnetic spin interactions. The combined experimental results confirmed that the SCHO powders crystallized in an orthogonal crystal structure with Pnma symmetry. The SEM images demonstrate that the powders exhibit a spherical morphology with particle sizes between 150 and 250 nm. XPS spectra verified the presence of Sr2+, Cr 3+/Cr4+, and Hf4+/Hfx+ (x < 4) ions in the SCHO powder. Oxygen was present as lattice oxygen and adsorbed oxygen species. At 2 K, the SCHO powder exhibited ferrimagnetic behavior with MS of 0.11 μB/f. u and a magnetic coercive field of 290 Oe. The SCHO ceramics displayed a normal butterfly‐like magnetoresistance‐magnetic field (MR‐H) curve at 2 K due to the intergranular tunneling effect, and the MR (2 K, 7 T) value was −2.05%. The temperature dependence of the resistivity of the SCHO ceramics revealed their semiconducting nature, and the electrical transport data in the temperature range 2−800 K were well fitted by the Mott's variable‐range hopping model, thermal activation model, and small polaron hopping model. Optical measurements demonstrate that the SCHO powders have a direct optical bandgap of 2.25 eV in the visible light window. Having both high TC and a direct optical bandgap (2.25 eV) makes SCHO oxides attractive for use in advanced spintronic devices and solar cells. [ABSTRACT FROM AUTHOR]

We propose here an experimental method to determine the magnetization compensation temperature of ferrimagnets. Our method utilizes the first-order derivative of the spontaneous net magnetization with respect to the temperature and then analyzes the results within the context of the Bloch's law of ferrimagnetic materials. This method enables us to extrapolate the compensation temperatures, even when they exceed the measurement limit. Consequently, a wide range of compensation temperatures can be determined using a single experimental setup. The present method provides a versatile tool for analyzing huge compensation temperature in the emerging field of ferrimagnetic and antiferromagnetic spintronics. [ABSTRACT FROM AUTHOR]

The effect of temperature on electrochemical properties of Ni82.3Cr7Fe3Si4.5B3.2 glassy alloy in different acid proticity has been investigated utilizing AC and DC methods. Firstly, the handling of experimental data on the temperature dependence of charge transfer resistance, as well as corrosion current density permits us to determine the values of classical Arrhenius parameters as well as the thermodynamic ones considered approximately independent of temperature. This leads us to deduce a global interpretation on the phenomenon of corrosion and polarization. Secondly, the deviation to the linearity of the Arrhenius behavior and the real dependence on temperature of the thermodynamic parameters, permit us to clearly quantify the effect of the acid proticity and define, for the first time, the concept of current Arrhenius parameters and the current thermodynamic ones, as well as the modeling of the enthalpy–enthalpy compensation. Moreover, the effect of temperature can be investigated using the Vogel–Fulcher–Tammann model to reveal that the corresponding Vogel temperature has an interesting physical meaning. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs), which are powered by Maxwell's displacement current, have a wide range of applications, including energy harvesting and self-powered sensors. However, very little attention has been paid to the effect of the ferromagnetic medium on TENG displacement current. Herein, flexible ferrimagnetic poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF–HFP))/nickel ferrite (NiFe 2 O 4) fiber composite film based TENGs were fabricated and their performances were analysed. Highly crystalline, ferrimagnetic NiFe 2 O 4 nanofibers with high aspect ratio were prepared using electrospinning technique by systematic optimization of spinning parameters. Thereafter, the fibers were reinforced into the polymeric matrix to improve the β–phase and dielectric constant which in turn significantly enhanced the TENG performance. The β–phase enhancement in the composite films was confirmed by XRD and FTIR analysis; 77 % of the β–phase was achieved with the incorporation of NiFe 2 O 4 fiber. Morphological features were examined using SEM and AFM, which revealed more β–phase spherulite formation in the composite films. A notable increase in the dielectric properties was evidenced with the addition of NiFe 2 O 4 fibers and a maximum dielectric constant of∼26 was attained at 100 Hz. The TENG was developed using P(VDF-HFP)/NiFe 2 O 4 and nylon which generated an output voltage (V pp) and current (I pp) values of 584 V and 25 μA, respectively. Furthermore, the performance of TENG under an external magnetic field was examined, and a notable improvement in performance was observed, paving the way for the application of NiFe 2 O 4 fibers in hybrid energy harvesters and self-powered sensors. [ABSTRACT FROM AUTHOR]

Soft ferrimagnetic spinel lithium based oxides were prepared with additives like V2O5 and Na2SiO3 and sintered with the efficient microwave sintering technique. Tetravalent metal ions substituents like Mn+4, Ti+4 were used to enhance the important properties like D. C. resistivity, saturation magnetization, permeability, hysteresis and dielectric behavior. The ferrites were sintered at different sintering temperatures viz., 900, 950 and 1000 °C for 10 min by microwave technique and by conventional technique at 1050 °C for 4h. X-ray diffraction (XRD) studied the structural behavior which confirmed the spinel characteristics, Scanning electron microscopy (SEM) and EDAX revealed the microstructural and elemental compositions respectively of the ferrites. The use of additives and the microwave sintering significantly influencing the microstructural behavior and subsequently on the electromagnetic properties could be observed. Studies of initial permeability and initial permeability loss found to remain nearly constant with change in frequency until at certain frequency they showed resonance behavior. The resonance frequency's dependence on the microstructures of the ferrites could be observed. Temperature dependence behavior of the dielectric parameters and the B-H loop traced from torroidal samples of the ferrites were studied. [ABSTRACT FROM AUTHOR]

The magnetic and magnetocaloric properties of a zigzag triangular nano-graphene with Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interactions in the mixed 1 and 3/2 spins are studied with the aid of the Monte Carlo investigations. The thermal magnetizations and the magnetic susceptibilities are considered. The phase diagram of the system and the variation of magnetizations with crystal field are established. The magnetic entropy for different external magnetic fields has been also sketched. The dependence of the field on the relative cooling power (RCP) of the system is found; the specific heat displacement of the system is displayed. Also, the adiabatic temperature of the system has been defined. Lastly, the magnetic hysteresis cycle with mixed spins S = 1 and σ = 3/2 for several different parameters is obtained. It can be observed that the values obtained for RCP rise with increasing external magnetic field and reduce with increasing N for constant parameters. The critical temperature values are also affected by the increasing number of non-magnetic layers. In addition, the effect of the RKKY interaction decreases as 1/N2. As a consequence, the system becomes rapidly out of order as the number of non-magnetic layers N is increased. [ABSTRACT FROM AUTHOR]

In this paper, we study the structural, magnetic, electronic, optical, thermoelectric, and thermodynamic properties of the perovskite ErMn0.5Fe0.5O3. The Wien2K code's implementation of density functional theory (DFT) was used to perform the first principle calculations for this compound utilizing the full potential linearized augmented plane wave form with Total Potential (FP-LAPW) approach. The GGA-PBE and the exchange–correlation potential with Hubbard correction (GGA+U) were used to calculte the bulk modulus, its first derivative, and the optimal lattice parameters. The compounds display metallic nature in the NM and FM states. While in the AFM state, the compound behaves as a half-metal. The electronic transport coefficients have been calculated. The entropy, thermal expansion coefficient, Debye temperature, and heat capacity Cv are calculated. The Monte-Carlo calculation method shows that the magnetization of this material undergoes a second-order transition at a temperature of Néel, TN = 248 K. [ABSTRACT FROM AUTHOR]

Nonreciprocal devices, including optical isolators, phase shifters, and amplifiers, are pivotal for advanced optical systems. However, exploiting natural materials is challenging due to their weak magneto‐optical (MO) effects, requiring substantial thickness to construct effective optical devices. In this study, it is demonstrated that subwavelength metasurfaces supporting bound states in the continuum (BICs) and made of conventional ferrimagnetic material can exhibit strong nonreciprocity in the Faraday configuration and near‐unity magnetic circular dichroism (MCD). These metasurfaces enhance the MO effect by 3–4 orders of magnitude compared to a continuous film of the same material. This significant enhancement is achieved by leveraging Huygens' condition in the metasurface whose structural units support paired electric and magnetic dipole resonances. The multi‐mode temporal coupled mode theory (CMT) is developed for the observed enhancement of the MO effect, and the findings with the full‐wave simulations are confirmed. [ABSTRACT FROM AUTHOR]

Light transition metals have recently emerged as a sustainable material class for efficient spin–charge interconversion. We report measurements of current-induced spin–orbit torques generated by Ni1−xCux alloys in perpendicularly magnetized ferrimagnetic Gd/Fe multilayers. We show that the spin–orbit torque efficiency of Ni1−xCux increases with the Ni/Cu atomic ratio, reaching values comparable to those of Pt for Ni55Cu45. Furthermore, we demonstrate magnetization switching of a 20-nm-thick Gd/Fe multilayer with a threshold current that decreases with increasing Ni concentration, similar to the spin–orbit torque efficiency. Our findings show that Ni1−x Cu x − based magnetic heterostructures allow for efficient control of the magnetization by electric currents. [ABSTRACT FROM AUTHOR]

We have investigated, for the first time, the hyperthermia properties, antibacterial, anticancer and antioxidant activities, as well as their toxicity, of Mn 0.25 Mg 0.25 Co 0.5 Fe 2 O 4 nanoparticles synthesized by the sol-gel auto-combustion method. X-ray diffraction results revealed a pure phase and good crystallinity of the synthesized. In addition, the Fourier transform infrared (FTIR) spectrum confirmed the formation of the crystallographic sites of the synthesized structure. In terms of morphology, scanning electron microscopy (SEM) showed that the nanoparticles were agglomerated. In addition, transmission electron microscopy (TEM) revealed that the nanoparticles had a cubic shape and a nanometric size of around 32 nm. Energy-dispersive X-ray spectroscopy (EDS) confirmed the chemical composition of the nanoparticles. With regard to magnetic properties, magnetic measurements showed almost ferrimagnetic behavior, with a saturation magnetization of 38.90 emu/g at room temperature. Hyperthermia measurements revealed relatively good heating efficiencies, with SAR value of 33W/g, good temperature rise and short time to reach magnetic hyperthermia temperature 42 °C (8 min). For biological activities the nanoparticles showed an excellent capacity to neutralize free radicals, eliminating 97% of DPPH and 95% of hydrogen peroxide. The dose of 40 mg/kg of the nanoparticles caused significant alterations in hematological and biochemical profiles. The material showed a significant effect on various bacterial strains, including Staphylococcus aureus and Bacillus subtilis. The synthesized nanoparticles also showed significant activity against various cell lines, including MCF-7 and HeLa. These results strongly suggest the promising utilization of Mn 0.25 Mg 0.25 Co 0.5 Fe 2 O 4 , in many applications as a potential candidate for magnetic-mediated hyperthermia. [ABSTRACT FROM AUTHOR]

This research is focused on designing new ceramic oxides with the spinel structure for a potential application as sensitive temperature and magnetic field sensors. In this respect, the mixtures of ferrimagnetic NiFe 2 O 4 with low-resistive Ni 0.66 Cu 0.41 Mn 1.93 O 4 semiconductor (molar coefficient α = 1 / 5 and 1 / 2) were prepared using the chemical co-precipitation technique followed by a low-temperature sintering of the cold-pressed powders. For the prepared materials, a variation of the electrical conductivity σ dc with temperature T (in the range 50 K–400 K) is quantitatively analyzed using different theoretical concepts of the charge carrier hopping transport occurring in disordered materials with strong electron-phonon interaction. It has been shown that an increase in α from 0 to 1 / 2 causes a step-like change of the dc electrical conductivity and, simultaneously, a gradual change in the magnetization M determined in the saturation state. The temperature coefficient of resistance T C R of the prepared ceramics takes the values from −0.6%/K (at 400 K) to −19.6%/K (below 100 K). The highest absolute value of the magneto-resistance coefficient M R determined at 150 K (and at magnetic field 7 T) registered for ceramic oxide with α = 1 / 2 was found to be 3.4%. [ABSTRACT FROM AUTHOR]

A Mn(II) salt and A+CN− under anaerobic conditions react to form 2‐D and 3‐D extended structured compounds of AmMnIIn(CN)m+2n stoichiometry. Here, the creation and characterization of this large family of compounds, for example AMnII3(CN)7, A2MnII3(CN)8, A2MnII5(CN)12, A3MnII5(CN)13, and A2MnII[MnII(CN)6], where A represents alkali and tetraalkylammonium cations, is reviewed. Cs2MnII[MnII(CN)6] has the typical Prussian blue face centered cubic unit cell. However, the other alkali salts are monoclinic or rhombohedral. This is in accord with smaller alkali cation radii creating void space that is minimized by increasing the van der Waals stabilization energy by reducing ∠Mn−N≡C, which, strengthens the magnetic coupling and increases the magnetic ordering temperatures. This is attributed to the non‐rigidity of the framework structure due the significant ionic character associated with the high‐spin MnII sites. For larger tetraalkylammonium cations, the high‐spin Mn sites lack sufficient electrostatic A+⋅⋅⋅NC stabilization and form unexpected 4‐ and 5‐coordinated Mn sites within a flexible, extended framework around the cation; hence, the size, shape, and charge of the cation dictate the unprecedented stoichio‐metry and unpredictable cation adaptive structures. Antiferromagnetic coupling between adjacent MnII sites leads to ferrimagnetic ordering, but in some cases antiferromagnetic coupling of ferrimagnetic layers are compensated and synthetic antiferromagnets are observed. The magnetic ordering temperatures for ferrimagnetic A2MnII[MnII(CN)6] with both octahedral high‐ and low‐spin MnII sites increase with decreasing ∠Mn−N≡C. The crystal structures for all of the extended structured materials were obtained by powder diffraction. [ABSTRACT FROM AUTHOR]

Chiral mesostructured NiFe2O4 films (CMNFFs) were synthesized using L -/ D -tyrosine as symmetry-breaking and structure-directing agents through a hydrothermal method. For the first time, chirality induced spin selectivity was directly observed in these ferrimagnetic materials using chirality-dependent magnetic-tip conducting atomic force microscopy (mc-AFM). [ABSTRACT FROM AUTHOR]

The magnetic susceptibility of Fe1 –xCoxCr2S4 solid solutions in the FeCr2S4-rich part of the FeCr2S4–CoCr2S4 system has been studied by static and dynamic methods. The magnetic measurements were performed at temperatures from 5 to 300 K in static (50 Oe and 45 kOe) and ac magnetic fields (field amplitude Hac = 1 Oe; ac field frequencies ν = 100, 1000, and 10 000 Hz). We have determined the temperatures of the magnetic transformations in the system and identified their nature. The results demonstrate that the temperature of the ferrimagnetic phase transition (TC) in Fe1 –xCoxCr2S4 increases with increasing cobalt content. The materials with x = 0–0.5 have been shown to undergo a transition to a spin glass state, evidenced by a shift of maxima in temperature dependences of the imaginary part of their dynamic susceptibility. [ABSTRACT FROM AUTHOR]

CoMn2O4, known for its extensive range of applications, has been subject to limited investigations regarding its structure dependent magnetic properties. Here, we have examined the structure dependent magnetic properties of CoMn2O4 nanoparticles synthesized through a facile coprecipitation technique and are characterized using x-ray diffractometer, x-ray photoelectron spectroscopy (XPS), RAMAN spectroscopy, transmission electron microscopy and magnetic measurements. Rietveld refinement of the x-ray diffraction pattern reveals the coexistence of 91.84% of tetragonal and 8.16% of cubic phase. The cation distribution for tetragonal and cubic phases are (Co0.94Mn0.06)[Co0.06Mn1.94]O4 and (Co0.04Mn0.96)[Co0.96Mn1.04]O4, respectively. While Raman spectra and selected area electron diffraction pattern confirm the spinel structure, both +2 and +3 oxidation states for Co and Mn confirmed by XPS further corroborate the cation distribution. Magnetic measurement shows two magnetic transitions, Tc1 at 165 K and Tc2 at 93 K corresponding to paramagnetic to a lower magnetically ordered ferrimagnetic state followed by a higher magnetically ordered ferrimagnetic state, respectively. While Tc1 is attributed to the cubic phase having inverse spinel structure, Tc2 corresponds to the tetragonal phase with normal spinel. In contrast to general temperature dependent H C observed in ferrimagnetic material, an unusual temperature dependent H C with high spontaneous exchange bias of 2.971 kOe and conventional exchange bias of 3.316 kOe at 50 K are observed. Interestingly, a high vertical magnetization shift (VMS) of 2.5 emu g−1 is observed at 5 K, attributed to the Yafet–Kittel spin structure of Mn3+ in the octahedral site. Such unusual results are discussed on the basis of competition between the non-collinear triangular spin canting configuration of Mn3+ cations of octahedral sites and collinear spins of tetrahedral site. The observed VMS has the potential to revolutionize the future of ultrahigh density magnetic recording technology. [ABSTRACT FROM AUTHOR]

The paper presents a study on the magnetic characteristics of hexagonal boron nitride using Monte Carlo simulations through the Metropolis algorithm. The study used the Blume-Capel Ising model to analyze the behavior of magnetizations and susceptibilities under the effect of the temperature, mixed exchange coupling, crystalline and external magnetic fields. The results show that the blocking temperature, where the magnetic atoms become magnetically frozen, increases as the exchange coupling interaction becomes weaker and as the external magnetic field increases. The findings indicate that the blocking temperature of the system is significantly influenced by the physical parameters employed in this study. Besides, the investigation at hand could serve as a foundation for researchers to innovate novel categories of spintronics and magnetic memory devices, featuring enhanced performance and functionality. [ABSTRACT FROM AUTHOR]

Due to their non-trivial topology, skyrmions describe deflected trajectories, which hinders their straight propagation in nanotracks and can lead to their annihilation at the track edges. This deflection is caused by a gyrotropic force proportional to the topological charge and the angular momentum density of the host film. In this article, we present clear evidence of the reversal of the topological deflection angle of skyrmions with the sign of angular momentum density. We measured the skyrmion trajectories across the angular momentum compensation temperature ( T AC ) in GdCo thin films, a rare earth/transition metal ferrimagnetic alloy. The sample composition was used to engineer the skyrmion stability below and above the T AC . A refined comparison of their dynamical properties evidenced a reversal of the skyrmions deflection angle with the total angular momentum density. This reversal is a clear demonstration of the possibility of tuning the skyrmion deflection angle in ferrimagnetic materials and paves the way for deflection-free skyrmion devices. [ABSTRACT FROM AUTHOR]

This work concerns the probabilistic analysis of particle‐based materials. More precisely, this work is devoted to the stochastic modeling of the geometric and constitutive microscale parameters associated with particle‐pair interactions of an existing model for particle‐based materials. Such an issue is addressed with a probabilistic methodology that relies on the maximum entropy principle from information theory. After defining and improving the chosen second‐gradient continuum model for particle‐based materials, it is shown that for micro‐homogeneous and micro‐isotropic materials, the involved microscale parameters turn out to be statistically independent. More precisely, the particle‐pair distance between two consecutive particles is a uniformly distributed random variable and the specific micro‐scale stiffness parameters are Gamma‐distributed random variables. A homogeneous and isotropic 2D concrete plate subjected to an axial load is considered for illustration purposes. A stochastic solver based on Monte Carlo numerical simulations and mixed finite element (FE) method are chosen. The FE discretization is applied to the weak formulation of the equivalent continuum model with random mechanical properties. On the contrary, the particle‐pair distance and the micro‐scale stiffness parameters, which are the parameters of the boundary value problem formulated for the equivalent continuum model, are modeled as random variables. Finally, uncertainties propagation is discussed and statistical fluctuations of the macro mechanical response are found to be significant. [ABSTRACT FROM AUTHOR]

We report different growth modes and corresponding magnetic properties of thin EuSe films grown by molecular beam epitaxy on BaF2, Pb1−xEuxSe, GaAs, and Bi2Se3 substrates. We show that EuSe grows predominantly in the (001) orientation on GaAs(111) and Bi2Se3, but along the (111) crystallographic direction on BaF2 (111) and Pb1−xEuxSe (111). High resolution transmission electron microscopy measurements reveal a sharp and highly crystalline interface for both (001) and (111) EuSe films. In agreement with previous studies, ordered magnetic phases include antiferromagnetic, ferrimagnetic, and ferromagnetic phases. In contrast to previous studies, we found a strong hysteresis of the antiferromagnetic–ferrimagnetic transition. The ability to grow epitaxial films of EuSe on Bi2Se3 and of Bi2Se3 on EuSe enables further investigation of interfacial exchange interactions between various phases of an insulating metamagnetic material and a topological insulator. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical and experimental analysis of nonlinear magnetic transmission lines and demonstrates the phenomenon and capability of a simultaneous rise and fall time compression. A theoretical approach is formulated in which a new version of the modified Korteweg–de Vries equation is developed utilizing the Gardner–Morikawa transformation, continuum limit approximation, Toda-lattice approximation, and Mei theory of Maxwellian circuits. The proposed theoretical foundation work is validated through experimental demonstration. The pulse generation in a nonlinear magnetic transmission line is then studied in detail, and the output pulse characteristics are explored under different magnetic field strengths and arbitrary magnetization directions. In particular, output waveforms are analyzed in terms of pulse amplitude, full width half maximum, detailed ringing level, and figure of merit. Magnetic losses that arise in the ferrite material are modeled. It is shown that these losses are responsible for originating dissipative effects, which in turn deteriorate pulse shaping and increase ringing level. The localized disturbance within ferrimagnetic materials is also studied, and its impact on the output waveforms is also discussed. This study can potentially open up a new and fruitful entry to explore magnetic materials and their impacts in the field of ultrafast electronics in parallel with nonlinear electrical transmission lines. [ABSTRACT FROM AUTHOR]

Spin-crossover (SC) compounds are fascinating materials that exhibit colorful phase transitions induced by temperature, pressure, photoirradiation, etc. From the microscopic point of view, the electronic (spin) state of a molecule changes between the low-spin (LS) and high-spin (HS) states by such stimuli, and a variation of the molecular size follows through the vibronic coupling between the electronic state and structure in the molecule. This causes an elastic distortion and then an elastic interaction. The elastic interaction is essential in cooperative properties of SC phenomena. In this paper, we present a tutorial study on elastic interaction models for SC phenomena, which are the recent trend of modeling of SC compounds. We focus on multistep transitions, which are a topic of SC phenomena. We analyze the phase diagrams including the metastable phases for several SC systems, in which antiferromagnetic-like and ferrimagnetic-like phases are associated in addition to the LS and HS phases. Making use of the phase diagrams, we show various patterns of thermally induced SC transition with steps. We also investigate SC transitions with steps in a core-shell SC nanocomposite composed of two different SC compounds. We focus on two cases: the core has a lower transition temperature than the shell, and the core has a higher transition temperature. We show characteristic features of difference in the two systems. [ABSTRACT FROM AUTHOR]

This study employs density functional theory to investigate the structural, elastic, electronic, and magnetic properties of FeVScSb and FeVYSb Heusler compounds. FeVScSb exhibits ferromagnetic properties in its stable state, whereas FeVYSb displays ferrimagnetic behavior. The obtained elastic constants (Cij) indicate that FeVScSb and FeVYSb possess mechanical stability and ductility, while also displaying a significant degree of elastic anisotropy. The aggregate magnetic moment of said alloys is determined to be equivalent to 3 μB, in accordance with the Slater–Pauling principle. The investigation of the impact of uniform strain on electronic and magnetic characteristics is conducted. The findings indicate that FeVScSb and FeVYSb exhibit semiconductivity within extensive lattice parameter intervals, ranging from 5.84 to 6.60 Å for FeVScSb and from 6.11 to 6.70 Å for FeVYSb. The Heusler compounds FeVScSb and FeVYSb exhibit half‐metallic behavior within a range of lattice parameters. Specifically, FeVScSb displays this behavior when the lattice parameter varies from 6.61 to 6.72 Å, while FeVYSb exhibits half‐metallicity within the range of 6.71–6.81 Å. Under the influence of strain, the magnetic moment retains a constant value of 3 μB. Therefore, the potential for spintronics is promising. [ABSTRACT FROM AUTHOR]

Ferrimagnets have received renewed attention as a promising platform for spintronic applications. Of particular interest is the Mn4N from the ε-phase of the manganese nitride as an emergent rare-earth-free spintronic material due to its perpendicular magnetic anisotropy, small saturation magnetization, high thermal stability, and large domain wall velocity. We have achieved high-quality (001)-ordered Mn4N thin film by sputtering Mn onto η-phase Mn3N2 seed layers on Si substrates. As the deposited Mn thickness varies, nitrogen ion migration across the Mn3N2/Mn layers leads to a continuous evolution of the layers to Mn3N2/Mn2N/Mn4N, Mn2N/Mn4N, and eventually Mn4N alone. The ferrimagnetic Mn4N, indeed, exhibits perpendicular magnetic anisotropy and forms via a nucleation-and-growth mechanism. The nitrogen ion migration is also manifested in a significant exchange bias, up to 0.3 T at 5 K, due to the interactions between ferrimagnetic Mn4N and antiferromagnetic Mn3N2 and Mn2N. These results demonstrate a promising all-nitride magneto-ionic platform with remarkable tunability for device applications. [ABSTRACT FROM AUTHOR]

A pure mixed-anion Fe(NH2trz)3(BF4)(SiF6)0.5 spin crossover complex is obtained implementing a solid–liquid post synthetic modification approach from the Fe(NH2trz)3(BF4)2 parent complex. This method allows obtaining highly crystalline powder samples incorporating homogeneous micrometric (1 μm long) rod-shaped particles. This compound presents an abrupt spin crossover behaviour with a narrow (10 K) hysteresis loop centred just above room temperature (320 K) which makes it very interesting for future integration into devices for various applications. [ABSTRACT FROM AUTHOR]