Search

Spin pumping from canted antiferromagnets is a cutting-edge topic in modern spintronics. The interest for fundamental and applied research that these materials arouse is related to their unusual structure, namely, with a small canting of the magnetic sublattices, which is explained by the presence of the Dzyaloshinskii–Moriya interaction. Through this effect, it becomes possible to experimentally study quasi-ferromagnetic resonance spectra and spin pumping in the range of tens of GHz at room temperature. In this paper, an experimental and theoretical investigation of spin pumping from an antiferromagnet with weak ferromagnetism, α -Fe 2 O 3 , is carried out. The conversion of the precession of the magnetization vector, excited by an alternating magnetic microwave field, into a constant voltage is realized using the inverse spin Hall effect in the hematite/heavy metal structure. Using a constant magnetic field up to 5 kOe, the resonant frequency of such a detector is tunable over a wide range up to 32 GHz with potential sensitivity reaching 10.1 μ V/W. Confirmation of the measurement of the spin current is the change in the sign of V sp when the polarity of the constant magnetic field alters. We believe that these studies will make a major contribution to the understanding of the physics of the spin-pumping effect from antiferromagnets and will also help in the development of devices for quantum technologies and next-generation communication technologies. [ABSTRACT FROM AUTHOR]

Spin pumping from canted antiferromagnets is a cutting-edge topic in modern spintronics. The interest for fundamental and applied research that these materials arouse is related to their unusual structure, namely, with a small canting of the magnetic sublattices, which is explained by the presence of the Dzyaloshinskii–Moriya interaction. Through this effect, it becomes possible to experimentally study quasi-ferromagnetic resonance spectra and spin pumping in the range of tens of GHz at room temperature. In this paper, an experimental and theoretical investigation of spin pumping from an antiferromagnet with weak ferromagnetism, α -Fe 2 O 3 , is carried out. The conversion of the precession of the magnetization vector, excited by an alternating magnetic microwave field, into a constant voltage is realized using the inverse spin Hall effect in the hematite/heavy metal structure. Using a constant magnetic field up to 5 kOe, the resonant frequency of such a detector is tunable over a wide range up to 32 GHz with potential sensitivity reaching 10.1 μ V/W. Confirmation of the measurement of the spin current is the change in the sign of V sp when the polarity of the constant magnetic field alters. We believe that these studies will make a major contribution to the understanding of the physics of the spin-pumping effect from antiferromagnets and will also help in the development of devices for quantum technologies and next-generation communication technologies. [ABSTRACT FROM AUTHOR]

In this paper, using variational methods and critical point theory we establish the existence of multiple solutions for a class of elliptic equations on Carnot groups depending on one real positive parameter and involving a subcritical nonlinearity. Some recent results are extended and improved. [ABSTRACT FROM AUTHOR]

This paper reports density functional theory (DFT) on LiMgP half Heusler alloy doped by the transition metal elements (Ti, V, Fe and Ni) determined by present results, in which the half-metallicity besides ferromagnetism behavior is estimated. The electron spin polarization of Ti(3 d) is around the E F and the Ti 2 + will have two electrons, of which two electrons occupied the e + . Then, this orbital is set on the Fermi level. When the conduction band of the orbitals e − , t 2 + and t 2 − is empty, LiMg 0. 9 5 Ti 0. 0 5 P displays the half-metallic characteristic, where the ferromagnetic (FM) conduct fits the double-exchange coupling. For LiMg 0. 9 5 V 0. 0 5 P alloy, the charge state is closer to V 2 + electron configuration, which predicts the following configuration, in which two electrons are occupied by e + and one electron is occupied by t 2 + at the upside of E F . Based on LiMg 0. 9 5 Fe 0. 0 5 P alloy, the presence of the half metallicity at the downside of E F due to (3 d) orbital is clear. A hybridization between the Fe(3 d) and the P(3 p) orbitals is in the range −0.35 — −0.04 Ry. For LiMg 0. 9 5 Ni 0. 0 5 P alloy, the predicted charge is Ni 2 + and exhibits the half-metallic on the downside of the E F which is occupied by t 2 − minority state. For LiMg 0. 9 5 TM 0. 0 5 P alloy, (TM = Ti, V, Fe and Ni), the half-metallic conduct is estimated with 100% spin polarized on the Fermi level. The spin moment of TM is ∥ M Ni ∥ < ∥ M Ti ∥ < ∥ M V ∥ < ∥ M Fe ∥ , where their total magnetic moments ∥ M Tot ∥ are in correlation for those Ni, Ti, V and Fe, where the trend also is ∥ M LiMg+ 0. 9 5 Ni 0. 0 5 P Tot ∥ < ∥ M LiMg 0. 9 5 Ti 0. 0 5 P Tot ∥ < ∥ M LiMg 0. 9 5 V 0. 0 5 P Tot ∥ < ∥ M LiMg 0.95 Fe 0. 0 5 P Tot ∥. Likewise, based on LiMg 0. 9 5 TM 0. 0 5 P alloys, the crystal field splitting (e , t 2) observation stated that the doped elements conduct a trend having the following range Δ (e , t 2) Ni < Δ (e , t 2) Ti < Δ (e , t 2) V < Δ (e , t 2) Fe . From these observations, it is predicted to have a correlation between magnetic moments of (Ti, V, Fe and Ni) and the crystal field splitting. [ABSTRACT FROM AUTHOR]

This review reports the latest trends in the ceramic composite matrix used for the magnetoelectric (ME) effect. In the last few years, ME composite has become the center of attraction for use in various electrically and magnetically coupled devices. The growth and use of electronic components everywhere have propulsively accelerated the exploration of self-powered electronic and sensor network devices. ME is a feasible technique for addressing difficulties of traditional batteries such as short life span and frequent recharge difficulties. Self-charging multiferroic components have been found for the constant working of mobile electronics that use multiferroic composites in response to magnetoelectric energy transformation. Researchers have rigorously studied the rigid and flexible magnetoelectric composites for their suitability in applications. This paper gives a comparative study between rigid and flexible magnetoelectric composites based on their properties and provides knowledge about the materials for such types of composites. It reviews the latest polymer-based ME materials as well as the related fabrication and polarization methods. The review finally encapsulates the applications in biomedicine, ranging from mechanical energy harvesters to sensors and actuators. [ABSTRACT FROM AUTHOR]

Copyright of Materials & Technologies / Materiali in Tehnologije is the property of Institute of Metals & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Intercalation of transition metal dichalcogenides with magnetic elements has been the subject of increasing research interest, aiming to explore novel magnetic materials with anisotropy and spin-orbit coupling. In this paper, two magnetic samples with varying Fe content have been prepared using different growth conditions via the chemical vapor transport method. A comprehensive investigation of the magnetic properties of the materials has been conducted using the Physical Property Measurement System (PPMS, Evercoolll-9T, Quantum Design). The results reveal distinct features in the studied materials. Fe0.12TaSe2 exhibits significant ferromagnetism with a Curie transition temperature of 50 K. However, its in-plane magnetism is weak and no significant hysteresis loop is observed below the Curie temperature. On the other hand, Fe0.2sTaSe2 exhibits antiferromagnetism without any hysteresis loop and has a Neel temperature up to 130 K. This finding is quite different from the intercalated iron in FexTaS2, where only an antiferromagnetic state occurs with x larger than 0.4. Our study thus provides updated insights into the magnetic properties of this new system and serves as a reference for future investigations of TaSe2 compounds with varying iron content. [ABSTRACT FROM AUTHOR]

Due to the strong interactions from multiple degrees of freedom at the interfaces, electron-correlated oxide heterostructures have provided a promising platform for creating exotic quantum states. Understanding and controlling the coupling effects at the oxide interface are prerequisites for designing emergent interfacial phases with desired functionalities. Here, we report the dimensional control of the interface coupling-induced ferromagnetic (FM) phase in perovskite-CaRuO3/infinite-layered-SrCuO2 superlattices. Structural analysis reveals the occurrence of chain-type to planar-type structural transitions for the SrCuO2 layer as the layer thickness increases. The Hall and magnetoresistance measurements indicate the appearance of an interfacial FM state in the originally paramagnetic CaRuO3 layers when the CaRuO3 layer is in proximity to the chain-type SrCuO2 layers; this superlattice has the highest Curie temperature of ~75 K and perpendicular magnetic anisotropy. Along with the thickness-driven structural transition of the SrCuO2 layers, the interfacial FM order gradually deteriorates and finally disappears. As shown by the X-ray absorption results, the charge transfer at the CaRuO3/chain-SrCuO2 and CaRuO3/plane-SrCuO2 interfaces are different, resulting in dimensional control of the interfacial magnetic state. The results from our study can be used to facilitate a new method to manipulate interface coupling and create emergent interfacial phases in oxide heterostructures. Harnessing Quantum States: A Breakthrough in Oxide Heterostructures Perovskite transition-metal oxides, known for their complex electron interactions, exhibit unique physical properties like superconductivity and magnetoresistance. However, layering these materials can result in new, unexpected behaviors at their interfaces. This study focuses on a layered structure of perovskite ruthenate and strontium cuprate. The research shows that by controlling the thickness of SCO layers in CRO/SCO superlattices, it is possible to induce ferromagnetism in CRO, which normally does not exhibit this property. The authors conclude that this manipulation of interface coupling can lead to new interfacial phases with potential applications in spintronics. The findings open up possibilities for future research into the control of quantum phases in complex oxide materials. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. In this paper, we report the dimensional control of the interface coupling-induced ferromagnetic phase in perovskite-CaRuO3/infinite-layered-SrCuO2 superlattices. The Hall and magnetoresistance measurements indicate the appearance of an interfacial ferromagnetic state in the originally paramagnetic CaRuO3 layers when the CaRuO3 layer is in proximity to the chain-type SrCuO2 layers; this superlattice has the highest Curie temperature of ~75 K and perpendicular magnetic anisotropy. Along with the thickness-driven structural transition from chain-type to planar-type of the SrCuO2 layers, the interfacial ferromagnetic order gradually deteriorates and finally disappears. [ABSTRACT FROM AUTHOR]

The search for magnetic topological materials has been at the forefront of condensed matter research for their potential to host exotic states such as axion insulators, magnetic Weyl semimetals, Chern insulators, etc. To date, the MnBi2 n Te3 n +1 family is the only group of materials showcasing van der Waals-layered structures, intrinsic magnetism and non-trivial band topology without trivial bands at the Fermi level. The interplay between magnetism and band topology in this family has led to the proposal of various topological phenomena, including the quantum anomalous Hall effect, quantum spin Hall effect and quantum magnetoelectric effect. Among these, the quantum anomalous Hall effect has been experimentally observed at record-high temperatures, highlighting the unprecedented potential of this family of materials in fundamental science and technological innovation. In this paper, we provide a comprehensive review of the research progress in this intrinsic magnetic topological insulator family, with a focus on single-crystal growth, characterization of chemical disorder, manipulation of magnetism through chemical substitution and external pressure, and important questions that remain to be conclusively answered. [ABSTRACT FROM AUTHOR]

This paper describes the contributions made by Władysław (Władek) Walukiewicz and his colleagues to the field of ferromagnetic semiconductor (FMS) alloys, such as (Ga,Mn)As. We focus on two key accomplishments. First, this team has predicted the formation of Mn interstitials in these materials, which have a profound effect on ferromagnetism in semiconductors. Additionally, identifying the conditions at which interstitials form has provided grounds for optimizing their ferromagnetic properties. Second, by applying the approach of band anticrossing to ferromagnetic semiconductors, this team has mapped out the properties of an Mn-derived impurity band in these materials. This is of particular importance in the field, because holes, which reside in the Mn-derived impurity band, are the very mechanism responsible for ferromagnetic order in FMSs. We discuss the effect that these accomplishments have on our understanding of FMSs and how they have contributed to progress in this area. We then describe the pathways that these achievements have opened up toward further progress in both basic and applied fronts of ferromagnetism in semiconducting systems; and we present our perspective on where additional work along the lines initiated by Władek Walukiewicz should be extended to further benefit this field. [ABSTRACT FROM AUTHOR]

Adding 10 wt% carbon fiber (CF) into graphene oxide (GO) dispersion were performed to fabricate CF10/reduced graphene oxide (rGO) film without the use of surfactants, binders or polymer matrices. The all-carbon CF10/rGO film possesses plausible tensile strength over one page of regular A4 printing paper and improved room-temperature ferromagnetism compared with the as-assembled rGO film, with saturation magnetization of about 0.327 emu/g and coercivity of about 100.4 Oe. The CF10/rGO composite with 50 wt% filler loading exhibits a good electromagnetic wave (EMW) absorption performance in the measured frequency range of 2–18 GHz. A minimal reflection loss reaches −34.3 dB@6.2 GHz (C-band), −35.4 dB@9.6 GHz (X-band), and −33.7 dB@13.1 GHz (Ku-band) with a thickness of 3.0 mm, 2.0 mm and 1.5 mm, respectively. The enhanced complex permittivity and permeability causing by the introduction of CF in rGO film are in favor of achieving an excellent impedance matching characteristic between the carbon materials and the air, responsible for more amount of EMW incidence; furthermore, localized electronic spin states and multi-relaxation processes arisen from the topological defects, oxygen-containing groups, and interfaces are ascribed to the enhanced microwave attenuation ability. • Ferromagnetic CF10/rGO film was fabricated free of surfactants, binders or polymer matrices. • The all-carbon CF10/rGO film possess plausible tensile strength over one page of regular A4 printing paper. • The enhanced microwave absorption properties were ascribed to the ideal impedance matching and multi-attenuation. [ABSTRACT FROM AUTHOR]

Ferromagnetism and superconductivity are two key ingredients for topological superconductors, which can serve as building blocks of fault-tolerant quantum computers. Adversely, ferromagnetism and superconductivity are typically also two hostile orderings competing to align spins in different configurations, and thus making the material design and experimental implementation extremely challenging. A single material platform with concurrent ferromagnetism and superconductivity is actively pursued. In this paper, we fabricate van der Waals Josephson junctions made with iron-based superconductor Fe(Te,Se), and report the global device-level transport signatures of interfacial ferromagnetism emerging with superconducting states for the first time. Magnetic hysteresis in the junction resistance is observed only below the superconducting critical temperature, suggesting an inherent correlation between ferromagnetic and superconducting order parameters. The 0-π phase mixing in the Fraunhofer patterns pinpoints the ferromagnetism on the junction interface. More importantly, a stochastic field-free superconducting diode effect was observed in Josephson junction devices, with a significant diode efficiency up to 10%, which unambiguously confirms the spontaneous time-reversal symmetry breaking. Our work demonstrates a new way to search for topological superconductivity in iron-based superconductors for future high Tc fault-tolerant qubit implementations from a device perspective. The authors study Josephson junctions where the superconductors are Fe(Te,Se) flakes and the weak link is just a 0.36 nm van-der-Waals gap between the two stacked flakes. They report global device-level transport signatures of interfacial ferromagnetism. [ABSTRACT FROM AUTHOR]

Indium sulfide (In2S3) is a promising candidate material for spintronic applications. In this article, undoped In2S3 nanoparticles with varying sizes were fabricated via a gas–liquid phase chemical method and annealing process. The In2S3 nanoparticles with small particle sizes are subjected to annealing treatment in a nitrogen atmosphere for the purpose of adjusting the surface-to-volume ratio of the nanoparticles and avoiding magnetic doping. Magnetic measurements indicate that these nanoparticles clearly exhibit a room temperature ferromagnetic behavior, which decreases with increasing size due to annealing. Intrinsic defects are believed to be responsible for the observed ferromagnetism, which is fully elucidated in terms of the bound magnetic polarons (BMPs) mechanism. Notably, the defect-related d0 ferromagnetism of the samples can be conveniently modulated by controlling the particle size. First principles calculations reveal that the p–d exchange interaction between unpaired S 3p electrons induced by the In vacancies and In 4d electrons is the primary origin of ferromagnetism in In2S3. The size-dependent magnetic properties of pure In2S3 nanoparticles not only suggest potential applications in future spintronics and magneto-optics, but also propose a novel strategy for the exploration of pure diluted magnetic semiconductors (DMSs). [ABSTRACT FROM AUTHOR]

In this paper, we establish the existence of global-in-time weak solutions for the Landau–Lifschitz–Gilbert equation with magnetostriction in the case of mixed boundary conditions. From this model, we derive by asymptotic method a two-dimensional model for thin ferromagnetic plates taking into account magnetostrictive effects. [ABSTRACT FROM AUTHOR]

Although extensive work has already been done on bulk La1−xSr1+xCoO4 layered oxides, there is very limited studies on their nano-crystalline nature, particularly for those with a higher Sr level (x ≥ 0.4), which may exhibit interesting magnetic properties and in particular photocatalytic properties because of their enhanced surface area. Moreover, the phases with higher Sr doping levels can be formed only at higher temperatures, which otherwise contain significant amounts of impurities. In order to synthesize them in a nanocrystalline form in the pure state at the lowest possible temperature, we applied a glycine nitrate combustion method using excess fuels for the synthesis of nanocrystalline La1−xSr1+xCoO4 (x = 0.0, 0.2, 0.4 and 0.6) layered perovskite oxides. Efforts were also made to synthesize phases with x > 0.6 but remained unsuccessful. The prepared nanophases were thoroughly characterized using PXRD, XPS, SEM, SQUID VSM and UV-DRS to examine the structural, morphological, optical, magnetic and photocatalytic properties. All the phases exhibit mixed valence states of +3 and +4 of Co, as confirmed by XPS analysis, which has a remarkable effect on various physical properties, especially magnetic and photocatalytic properties. An abrupt transition in magnetic behaviour from antiferromagnetic for x = 0 and 0.2 phases to ferromagnetic in case of x = 0.4 and 0.6 was observed. The optical band gap values (Eg) of all the synthesized nanophases obtained from DRS are in the visible range (1.57 to 1.47 eV), which make them suitable and reliable photocatalysts for dye degradation. Moreover, the synthesized nanophases were assessed for their photocatalytic activity by employing rhodamine B (RhB) dye as a model contaminant. The results revealed that the La0.4Sr1.6CoO4 photocatalyst efficiently and swiftly degraded RhB within 60 min. Considering the performance of the La0.4Sr1.6CoO4 photocatalyst, the study was expanded to include the degradation of other organic dye pollutants, namely, methyl orange (MO), methylene blue (MB) and a ternary combination of these contaminants (RhB + MB + MO). [ABSTRACT FROM AUTHOR]

The effect of Ru-substitution (5–15 %) on the charge ordering of Y 0.5 Ca 0.5 MnO 3 has been investigated in this paper. Ru, existing in different oxidation states such as Ru4+ and Ru5+, plays an immense role in causing ferromagnetic (FM) superexchange interactions with Mn3+ ions. This, combined with the FM double-exchange interactions between Mn3+ and Mn4+ ions, destroys charge ordering. The development of ferromagnetism in Ru-substituted compounds is understood experimentally through the remarkable enhancement of dc magnetization with a simultaneous shift of T C from 57 K to 95 K with increasing Ru content from x = 0.05 to x = 0.15. The appearance of hysteresis for higher doping concentrations further confirms the FM nature. Concomitant with the favorable impact on the magnetic nature, there is also a development of magnetocaloric properties upon Ru-substitution. The maximum magnetic entropy change for x = 0.05 to 0.15 that was found to peak at T C ranges from 1.08 J/kg/K to 2.8 J/kg/K respectively for a field change of 9 T. The corresponding relative cooling power (RCP) increases from 76 J/kg to 324 J/kg indicating a significant growth of RCP with Ru substitution. These salient features of Ru-doped Y 0.5 Ca 0.5 MnO 3 would make it a suitable candidate for magnetic refrigeration. [ABSTRACT FROM AUTHOR]

In the current paper, we have prepared Cu0.66‐xZn0.34+xSe materials by varying the concentration of copper and zinc (x=0, 0.085, 0.17, 0.255, 0.34) with the help of a facile one‐step hydrothermal method. The X‐ray diffraction study reveals that the as‐prepared nanomaterials show the polycrystalline property. The crystallinity increases with the variation of Zn concentration, and the average crystallite size was calculated in the 39 to 55 nm range. The morphological analysis shows the uniform and agglomerated particles having an average size of around 596 nm. High‐resolution transmission electron microscopy and selected area electron diffraction study reveal the crystalline phases of the prepared sample. The energy‐dispersive X‐ray analysis confirmed the presence of constituent elements in the sample. The sample shows a high optical bandgap in the range of 3.6 eV to 4.09 eV, which was calculated from absorbance spectra. Photoluminescence measurements of the samples were carried out with 532 nm laser excitation, where the defect‐related emission peaks in the 540–850 nm range are observed. A change in the bandgap and optical emission is observed for different compositions. The magnetic properties analysis through the vibrating sample magnetometer reveals that the prepared sample exhibits ferromagnetic behaviour at room temperature, which can be used in magnetic storage applications. The tuning of the optical properties of the samples by varying the copper and zinc concentrations will be useful for various photonic devices. [ABSTRACT FROM AUTHOR]

In this paper, we report the induced magnetization in metallic and semiconducting SiCNTs on the adsorption of transition metals. The resultant adsorbed SiCNTs structures showed half-metal-ferromagnetic and ferromagnetic behaviour verifying the induced magnetization. The spin-density of states and bandstructure have also been studied, confirming the induced magnetic behaviour. The strength of the induced ferromagnetic behaviour is varied with the various transition metals and is then related to the calculated magnetic moment in the adsorbed structure. The Cr adsorbed (8,0) SiCNT indicated strong half- metal-ferromagnetic behaviour with a magnetic moment of 5.4 μ B . Only Cu-adsorbed (6,0) metallic SiCNT showed ferromagnetic behaviour among all the simulated structures indicating the impact of transition metal on the SiCNT structures. These promising results will be helpful in designing of devices like spin-valves, MTJs, and MRAMs in the field of spintronics. [ABSTRACT FROM AUTHOR]

Layer‐ and stacking‐dependent interlayer magnetism observed in bilayer CrI3${\rm CrI}_3$ has attracted a lot of attention recently. Although considerable efforts have been made, the interlayer exchange mechanism still lacks a clear physical picture. In this paper, orbital overlap‐dependent super‐super‐exchange (SSE) interactions are proposed to understand the interlayer magnetism of bilayer MX3${\rm MX}_3$ (M = Cr, Fe, and Mo; X = Cl, Br, and I) with different stacking orders. The detailed atom‐ and orbital‐resolved magnetic exchange couplings are evaluated to reveal the underlying mechanism. The results suggest that the interlayer magnetic ground state of all FeX3${\rm FeX}_3$ bilayers are antiferromagnetism (AFM) due to the t2g3eg2$t_{2g}^{3}e_{g}^{2}$ electronic configuration of Fe3+${\rm Fe}^{3+}$ cation. While CrX3${\rm CrX}_3$ and MoX3${\rm MoX}_3$ are found to possess stacking‐dependent interlayer magnetism due to the competition between AFM and ferromagnetism (FM), the dominant interlayer AFM exchange couplings are the eg−eg$e_{g}-e_{g}$ and t2g−t2g$t_{2g}-t_{2g}$ for CrX3${\rm CrX}_3$ and MoX3${\rm MoX}_3$, respectively, indicating different underlying mechanisms. These distinct interlayer magnetism can be consistently understood by the number and strength of SSE paths, which can be determined by the rule based on the orbital overlap of mediating anions. Moreover, the atom‐ and orbital‐resolved magnetic exchange couplings are also evaluated in detail, which are in good agreement with the above qualitative mechanism. This work provides detailed information and insight for understanding the stacking‐dependent interlayer magnetism, which is beneficial for the application of 2D magnetic materials. [ABSTRACT FROM AUTHOR]

A high perovskite activity is sought for use in magnetic applications. In this paper, we present the simple synthesis of (2.5% and 5%) Tellurium-impregnated-LaCoO3 (Te-LCO), Te and LaCoO3 (LCO) by using a ball mill, chemical reduction, and hydrothermal synthesis, respectively. We also explored the structure stability along with the magnetic properties of Te-LCO. Te has a rhombohedral crystal structure, whereas Te-LCO has a hexagonal crystal system. The reconstructed Te was imbued with LCO that was produced by hydrothermal synthesis; as the concentration of the imbuing agent grew, the material became magnetically preferred. According to the X-ray photoelectron spectra, the oxidation state of the cobaltite is one that is magnetically advantageous. As a result of the fact that the creation of oxygen-deficient perovskites has been shown to influence the mixed (Te4+/2−) valence state of the incorporated samples, it is abundantly obvious that this process is of utmost significance. The TEM image confirms the inclusion of Te in LCO. The samples start out in a paramagnetic state (LCO), but when Te is added to the mixture, the magnetic state shifts to a weak ferromagnetic one. It is at this point that hysteresis occurs due to the presence of Te. Despite being doped with Mn in our prior study, rhombohedral LCO retains its paramagnetic characteristic at room temperature (RT). As a result, the purpose of this study was to determine the impacts of RT field dependency of magnetization (M-H) for Te-impregnated LCO in order to improve the magnetic properties of RT because it is a low-cost material for advanced multi-functional and energy applications. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate that V0.027Bi0.973TeI, a material with both giant bulk Rashba effect and ferromagnetism, can reverse its magnetization by self-generated spin–orbit torque. Through first-principles calculation, it is found that the giant bulk Rashba effect arises from both bulk space inversion asymmetry and strong spin–orbital coupling, while the ferromagnetism originates from the itinerant d-electrons of doped element vanadium. More importantly, its field-like spin–orbit torque efficiency is determined to be as high as 4.53 × 10−4 mT/(A cm−2), which is more than two orders of magnitude higher than that typically observed in magnetic heterostructures. It is further shown that by using such magnetic bulk Rashba material to form a homogenous spintronic device, the power consumption for magnetization switching can be significantly reduced. [ABSTRACT FROM AUTHOR]

The exchange coupling, represented by the J parameter, is of tremendous importance in understanding the reactivity and magnetic behavior of open-shell molecular systems. In the past, it was the subject of theoretical investigations, but these studies are mostly limited to the interaction between metallic centers. The exchange coupling between paramagnetic metal ions and radical ligands has hitherto received scant attention in theoretical studies, and thus the understanding of the factors governing this interaction is lacking. In this paper, we use DFT, CASSCF, CASSCF/NEVPT2, and DDCI3 methods to provide insight into exchange interaction in semiquinonato copper(II) complexes. Our primary objective is to identify structural features that affect this magnetic interaction. We demonstrate that the magnetic character of Cu(II)-semiquinone complexes are mainly determined by the relative position of the semiquinone ligand to the Cu(II) ion. The results can support the experimental interpretation of magnetic data for similar systems and can be used for the in-silico design of magnetic complexes with radical ligands. [ABSTRACT FROM AUTHOR]

Double perovskite oxides have gained tremendous attention in material science and device technology due to their facile synthesis and exceptional physical properties. In this paper, we elucidate the origin of magnetisation in non-magnetic double perovskite oxides Sr2MSbO6 (M = Al, Ga) induced by non-magnetic 2p impurities (C and N) substituted. The calculations were done within the full potential linearised augmented plane wave method in the framework of the density functional theory. The exchange–correlation potential is evaluated using the generalised gradient approximation (GGA) of Perdew–Burke–Ernzerhof and the modified Becke and Johnson (mBJ-GGA). Regarding structural properties of undoped double perovskites Sr2MSbO6 (M = Al, Ga), we found that the lattice constants and oxygen positions are in rational accord with the experimental results. Furthermore, both of the examined compounds are brittle in nature with isotropic character. For Sr2AlSbO6, we have got the values of energy gap equal to 1.9 and 3.7 eV within the GGA and the mBJ-GGA, respectively. However, for Sr2GaSbO6 the values of energy gap obtained in GGA and mBJ-GGA are equal to 0.8 and 2.9 eV, respectively. Finally, spin-polarised calculations reveal that the doping C and N can lead to drastic changes in the magneto-electronic properties of the semiconducting Sr2MSbO6 matrix with the integer magnetic moment of 6.00 μB and exhibit half-metallic properties. The origin of ferromagnetism can be attributed to the spin–split impurity bands inside the energy gap of the semiconducting Sr2MSbO6 matrix. These results may help experimentalists in synthesising new double perovskites for spintronic applications. [ABSTRACT FROM AUTHOR]

This paper presents the results of measuring the main parameters of the ferromagnetic and spin-wave resonance spectra (resonant field, linewidth, and intensity) of single-layer permalloy films at various angles in the out-of-plane orientation. The effect of the type of surface conditions on the angular dependence of the intensity ratio of adjacent modes is studied. A correspondence is established between the angle of the applied constant magnetic field with respect to the normal to the film and the change in the oscillation type from uniform to nonuniform. The revealed features of the angular dependences of the resonant field and the intensity of the spectral peak can be successfully used in the identification of microwave spectra. The fundamental magnetic parameters (effective magnetization, exchange interaction constant, surface anisotropy constant, and perpendicular anisotropy field) were determined. [ABSTRACT FROM AUTHOR]

A longstanding problem in natural science and later in physics was the understanding of the existence of ferromagnetism and its disappearance under heating to high temperatures. Although a qualitative description was possible by the Curie–Weiss theory, it was obvious that a microscopic model was necessary to explain the tendency of the elementary magnetons to prefer parallel ordering at low temperatures. Such a model was proposed in 1922 by Schottky within the old Bohr–Sommerfeld quantum mechanics and claimed to explain the high values of the Curie temperatures of certain ferromagnets. Based on this idea Ising formulated a new model for ferromagnetism in solids. Simultaneously the old quantum mechanics was replaced by new concepts of Heisenberg and Schrödinger and the discovery of spin. Thus Schottky's idea was outperformed and finally replaced in 1928 by Heisenberg exchange interaction. This led to a reformulation of Ising's model by Pauli at the Solvay conference in 1930. Nevertheless one might consider Schottky's idea as a forerunner of this development explaining and asserting that the main point is the Coulomb energy leading to the essential interaction of neighboring elementary magnets. [ABSTRACT FROM AUTHOR]

In this paper, the design of a Giant Magneto Resistive (GMR) sensor is optimized using single-objective optimization algorithms, for measuring magnetic nanoparticles stored in an Eppendorf tube. The iron oxide nanoparticle (Fe3O4) is employed as a magnetic nanoparticle. The variance-based sensitivity analysis is used to identify the most significant variable affecting the GMR sensitivity which is found to be the magnetic bias. As a result, using single-objective optimization algorithms, the optimal value for GMR sensor magnetic bias value (H) was computed and incorporated in the instrument design. The device thus designed was fabricated using Rapid Prototyping (RPT)-solid works. To identify the sensor response in a linear range, a couple of permanent neodymium magnets were used to provide horizontal and vertical magnetic fields for sensor bias and nanoparticle magnetization. This process gives an idea of a combined hardware-software approach, to reduce the measurement uncertainty and increase the system's sensitivity. The proposed design achieved an output signal change of 248 mV for a magnetic particle concentration change of 1 µg. The device's lowest measurable concentration was improved using the appropriate single-objective optimization technique, resulting in 36 ng as the lowest measurable concentration. The performance of the optimal GMR device design was analyzed for hysteresis analysis Fe3O4, Distance vs Sensor output for various input voltages, Temperature performance and SEM analysis of Fe3O4. The average nanoparticle size range is measured as 97 nm from SEM analysis. [ABSTRACT FROM AUTHOR]

Since the confirmation of long‐range magnetic ordering in 2D materials, much effort has been devoted to finding more 2D magnetic materials with high Curie temperature (TC) and tunable physical properties. Most of the 2D magnets realized to date are based on van der Waals (vdW) materials, but recently synthesized 2D non‐vdW ultrathin materials have revealed an alternative direction for the discovery of novel 2D magnets. In this paper, a family of 2D non‐vdW Cr2TexSe3−x compounds is proposed. All Cr2TexSe3−x compounds are predicted to be energetically favorable and air stable, suggesting experimental feasibility, and long‐term stability. Compared to other non‐vdW materials, Cr2TexSe3−x compounds have superior oxidation resistance. Moreover, they exhibit obvious composition‐dependent magnetic ordering, which originates from the competition between interlayer direct antiferromagnetic exchange and ferromagnetic superexchange. Among them, half‐metals Cr2Te3 and Cr2TeSe2 exhibit robust ferromagnetism with high TC values of 396 and 261 K, respectively. Additionally, 2D Cr2TeSe2 shows a sizable anomalous Hall conductivity of 6237 Ω cm−1. The present results enrich the database of 2D non‐vdW magnets and provide fundamental understanding about the composition‐induced magnetic phase transition, which may be of use in spintronic applications. [ABSTRACT FROM AUTHOR]

This paper presents a dual gravity model for a (2+1)‐dimensional system with a limit on finite charge density and temperature, which will be used to study the properties of the holographic phase transition to paramagnetism‐ferromagnetism in the presence of Horndeski gravity terms. In our model, the non‐zero charge density is supported by a magnetic field. As a result, the radius ρ/B$\rho /B$ indicates a localized condensate, as the Horndeski gravity parameter is increased, that is represented by γ. Furthermore, such condensate shows quantum Hall‐type behavior. This radius is also inversely related to the total action coefficients of our model. It is observed that increasing the Horndeski parameter decreases the critical temperature of the holographic model and leads to the harder formation of the magnetic moment at the bottom of the black hole. However, when removing the magnetic field, the ferromagnetic material presents a disorder of its magnetic moments, which is observed through the entropy of the system. The authors also found that at low temperatures, spontaneous magnetization and ferromagnetic phase transition. [ABSTRACT FROM AUTHOR]

This paper investigates the properties of cubic halides KCrX3 (X = Cl, Br, I) compounds focusing on their half-metallic (HM) ferromagnetic and thermoelectric characteristics. The analysis is performed using the Wien2k and BoltzTrap coding. The stability of our compounds in the ferromagnetic (FM) phase is established by the higher energy release compared to the antiferromagnetic (AFM) phase. The calculated value of Poisson ratio and Pugh ratio greater than their cutoff limit (0.26 and 1.75) reveal that our examined materials are ductile in nature. To examine the electronic structure, the Trans-Bhala modified Becke Johnson potential (TB-mBJ) is employed to investigate half-metallic nature. The density of states (DDS) analysis indicates significant contributions from X-p states in the valence band and Cr 3d-states in the conduction band. A comparative analysis of crystal field (ΔEcrystal) and exchange (indirectΔx(Pd) and direct Δx(d)) energies provides insights into the primary role of electronic spin in the ferromagnetic behavior. The observed value (4 μB) of total magnetic moment of the investigated halide perovskites suggest that they could be promising candidates for spintronic materials. Lastly, we compute the thermoelectric parameters within a temperature range of 200 K to 800 K to explore the potential application in renewable energy devices. [ABSTRACT FROM AUTHOR]

The soliton wave solutions to the (2+1)-dimensional Heisenberg ferromagnetic spin chain (ℋ ℱ ) problem are explored in this paper. The (2+1)-dimensional ℋ ℱ equation describes the nonlinear spin dynamics of Heisenberg ferromagnetic spin chains in the semiclassical limit. This formula is based on the spin-chain of the Heisenberg field. The bilinear and anisotropic interactions are accounted for in this equation. Even ferromagnetism may be explained by this paradigm, since it describes the propagation of waves inside a substance (the magnetic ordering in ferromagnetic materials). To construct a new soliton wave solution and validate its correctness, modern analytical and approximative schemes are utilized such as the Khater II and Adomian decomposition methods. Numerous interpretations for solitary waves are shown by various plots such as polar plots, contour plots, two-dimensional plots, and three-dimensional plots. The study's novelty may be appreciated by contrasting our findings with those presented in previously published research publications. Most of the many computational simulations used are performed with the aid of a program called Mathematica 13.1. [ABSTRACT FROM AUTHOR]

In this paper, the features of current magnetic and electric flow densities are investigated. Their geometric phases computed through the local anholonomic reference frame are investigated for the normal flow of the electromagnetic field lines in ordinary geometry. The normal evolution field-based reference frame, which specifies the time-dependent flow of the curve in terms of geometric quantities, is given. The relationship of the gradient of the flow flux and the divergence freeness of the magnetic field is introduced. Thus, the aim is to elucidate the efficient use of the anholonomic coordinate system and its components and also to determine the conditions for the existence of electromagnetic field vector flux surfaces governed by evolution equations in the normal direction when they are exposed to the modified visco Heisenberg ferromagnetic effect. [ABSTRACT FROM AUTHOR]

MoS2 is a typical two-dimensional material with promising optical and electrical properties. The realization of ferromagnetism in MoS2 is important for its applications in semiconductor spintronics. A facile technique should be developed to induce the ferromagnetism in MoS2, and the possible extrinsic contribution should be avoided. In this paper, flower-like MoS2 nanostructures were fabricated by the hydrothermal method. X-ray diffraction spectra show the 1 T/2H mixed phases of as-prepared MoS2 nanostructures, which changes to pure 2H structure after the O plasma treatment. Raman spectra confirm the existence of Mo–O bonding, which is further confirmed by the X-ray photoelectron spectra after the O plasma treatment. Magnetization measurements at 300 K show the weak ferromagnetism in the as-prepared MoS2, with saturated ferromagnetic magnetization of 0.0012 emu/g. After the O plasma treatment, the weak ferromagnetism is strongly enhanced with saturated ferromagnetic magnetization of 0.0343 emu/g. First principle calculation has been performed to disclose the possible origin of ferromagnetism. Significant overlapping between the density of states of O and Mo, or O and S has been observed. The magnetic contribution from Mo and S is negligible, while O takes the main role for the enhanced ferromagnetism. [ABSTRACT FROM AUTHOR]

The original definition of multiferroics is that one owns two or three "ferro" properties, such as ferroelectricity, ferroelasticity, and ferromagnetism. Furthermore, novel effects would be generated by the cross-coupling effect among various orders of multiferroic materials, and it has a broad application prospect in electronic information, sensing, storage, wireless network and other fields. At present, researchers are still focus on the multiferroic materials with strong magnetoelectric coupling effect at room temperature. However, the realization and application of devices based on multiferroics are still on the way. Strain engineering is an effective way that can influence the physical properties of multiferroic materials. The physical properties of materials such as electricity, magnetism, and photoacoustic could be influenced by strain engineering through the interaction of lattice with electrons, spins, and orbits. Tuning the structural and physical properties of ferroelectric thin films by strain has been paid extensive attention. Through investigating the research of strain engineering in multiferroic materials in this paper, herein, the strain engineering in multiferroics are summarized and effect of strain engineering on the physical properties of multiferroics is reviewed. It is prospected that the current work may provide research ideas for the investigation and development of multiferroic materials. [ABSTRACT FROM AUTHOR]

Bismuth ferrite (BFO) nanostructures and thin films have gained attraction as suitable candidates for energy storage and energy conversion due to their high energy storage efficiency, temperature stability and low dielectric loss. Electrical properties of such multiferroic materials are tailored by ferroelectric and ferromagnetic constituents and have opened up amazing avenues in electrochemical supercapacitor and photovoltaic applications. Dopants play a significant role in optimizing the magnetic and dielectric properties of such materials owing to suitable applications. This review highlights the scientific advancements reported in BFO nanostructures for energy applications by optimizing their magnetic and dielectric properties. This paper starts with a brief introduction of BFO and a discussion on the effects of various dopants by different synthesis techniques, and their effects on the magnetic and dielectric properties are also portrayed. Eventually, this review summarizes the various doping effects, which paves way for future research on this multiferroic material. [ABSTRACT FROM AUTHOR]

In this paper, we have performed a first-principles study to investigate the electronic structure, magnetic, mechanic and anisotropic elastic properties of Cu2CrZ (Z=Si and Ge) Full Heusler alloys. The study of these characteristics shows thermodynamic and mechanical stability with cubic symmetry in our compounds and they also have an anisotropic character. The ground-state parameters, i.e., lattice constant, the bulk modulus and the electronic structure are calculated using the full-potential linearized augmented plane wave (FP-LAPW) approach to the density functional theory (DFT) within the generalized gradient approximation (GGA+WC) for the exchange and correlation potential. The objective is to seek stable metallic ferromagnet materials. [ABSTRACT FROM AUTHOR]

This paper reports the coexistence of room-temperature ferroelectricity and ferromagnetism in double perovskite Bi2CoMnO6 ceramics synthesized by using the sol–gel combustion technique. X-ray diffraction analysis shows that the pure phase formation of Bi2CoMnO6 takes place in the sample calcined at 600 °C. XRD data is refined using Rietveld analysis. The morphology of the as-prepared ceramics was studied using SEM micrographs. The origin of multiferroic configuration in this compound is due to coupling of the long-range electric field of Bi 6s2 lone pair electrons with long-range spin order of Co–O–Mn, Co–O–Co and Mn–O–Mn orbitals. Ferroelectricity is also confirmed by positive-up and negative-down measurements. A remanent magnetization of Mr 7.4 × 10−3 emu/g and remanent polarization 2Pr = 0.33 μC/cm2 were observed. [ABSTRACT FROM AUTHOR]

This paper discusses an outstanding issue in philosophy of physics concerning the relation between quantum symmetries and the notion of physical equivalence. Specifically, it deals with a dilemma arising for quantum symmetry breaking that was posed by Baker (Philos Sci 78:128–148, 2011), who claimed that if two ground states are connected by a symmetry, even when it is broken, they must be physically equivalent. However, I argue that the dilemma is just apparent. In fact, I object to Baker's conclusion by showing that the two thermodynamical phases of a ferromagnet, which are connected by the so-called flip-flop symmetry, are physically inequivalent, thereby providing a counter-example to his claim. [ABSTRACT FROM AUTHOR]

A phenomenological theory is explored for itinerant weak ferromagnetism. Free energy including the higher order terms of m 4 and h m 3 is introduced and examined. This free energy is derived from the mean-field free energy expression with the use of the Bragg–Williams entropy. We apply the present theory to the typical itinerant weak ferromagnetic materials ZrZn 2 , MnSi 2 , and others. To determine the model parameters, we use the experimental value of the magnetization under the large magnetic field or the extension of the Arrott plot with a functional form of hyperbola. This extended Arrott plot would explain various experimentally observed M–H curves at finite temperatures. Finally, we discuss the Sommerfeld coefficient in magnetic fields based on the present theory. [ABSTRACT FROM AUTHOR]

We study the effect of hole doping on the Kitaev spin liquid (KSL) and find that for ferromagnetic (FM) Kitaev exchange K the system is very susceptible to the formation of a FM spin polarization. Through density matrix renormalization group simulations on finite systems, we uncover that the introduction of a single hole, corresponding to ≈1% hole doping for the system size we consider, with a hopping strength of just t ~ 0.28K is enough to disrupt fractionalization and polarize the spins in the [001] direction due to an order-by-disorder mechanism. Taking into account a material relevant FM anisotropic exchange Γ drives the polarization towards the [111] direction via a transition into a topological FM state with chiral magnon excitations. We develop a parton mean-field theory incorporating fermionic holons and bosonic magnons, which accounts for the doping induced FM phases and topological magnon excitations. We discuss experimental implications for Kitaev candidate materials. [ABSTRACT FROM AUTHOR]

Transition-metal doped topological insulators have been widely explored since the observation of quantum anomalous Hall effect (QAHE). Subsequently, the magnetic (Pb,Sn)(Te,Se) was predicted to possibly possess a high-temperature QAHE state. However, the fundamental understanding of Cr-doping-induced ferromagnetism in this system remains unclear. Here, we report the stable ferromagnetism in the high-crystalline Cr-doped SnTe films. Upon Cr doping, the magnetoconductance unveils a crossover from weak antilocalization to weak localization. Further increasing the Cr concentration to Cr0.17Sn0.83Te introduces a strong ferromagnetism with a Curie temperature of ~140 K. We detected a sizable spin moment ms = 2.28 ± 0.23 μB/Cr and a suppressed orbital moment ml = 0.02 μB/Cr. Cr dopants prefer to substitute the Sn sites and behave as divalent cations, as indicated by the experimental results and density function theory calculations. The controllable growth of magnetic SnTe thin films provides enlightenment towards the high-temperature QAHE in magnetic TCIs for the desired dissipationless transport in electronics. [ABSTRACT FROM AUTHOR]