Room Temperature Ferromagnetism Research Articles

Synthesis and multifunctional characterizations of Gd2 O3 and Sm2 O3 modified ZnO nanoparticles

In the present communication multifunctional characterizations suitable for spintronics and memory storage devices are described. Double doped (Gd3+, Sm3+) ZnO nanoparticles are prepared from Sol-Gel method using poly vinyl alcohol (PVA) as chelating agent. The as prepared powders are annealed at 500 °C–1000 °C with a step size of 100 °C. The genesis of single phase hexagonal wurtzite structure, morphological and topographical changes, optical, magnetic and mechanical properties were studied with XRD (X-ray diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), EDS (energy dispersive spectroscopy), UV- DRS (ultraviolet diffuse reflective spectroscopy), PL (photoluminescence), VSM (vibrating sample magnetometer) and pin on disc tribometer. XRD study untangled the crystallite size and found to be in the range23-50nm. Polycrystalline nanoparticles of spherical geometry with induced porosity is observed from SEM study. The particle size associated with the samples annealed at 500 °C and 900 °C is 24 nm and 27 nm respectively from TEM study. Analyzed the proximity of functional groups, molecular vibrations in the range of 400-4000 cm−1 employing FTIR (Fourier transform infrared spectroscopy). EDS results revealed the stoichiometry of the produced samples. The pronounced optoelectronic applications of Zn1-x Gdx Smx O (ZGS) can be attributed to the large band gap (3.50–3.02 eV) associated with the materials with rise in annealing temperature. The room temperature ferromagnetism was evidenced with double doped ZnO nanomaterials. The wear coefficient, and friction coefficient were evaluated using pin-on-disc tribometer. The utility of materials as solid state lubricants was confiscated from the range of frictional coefficient values (0.067–0.893).

New spin-electronics compositions: Large ferromagnetic order of BaSn0.98-xFe0.02CuxO3 (x = 0.02, 0.04, 0.06) semiconductor

Inducing robust ferromagnetic order in dilute magnetic semiconductor materials is an essential topic for spin-based electronics devices. Herein, the escalating concentration of nonmagnetic Cu ions was employed to strongly reinforce the room temperature ferromagnetism of 2% Fe doped BaSnO3 structure. BaSn0.98-xFe0.02CuxO3 (x = 0.02, 0.04 or 0.06) compositions were prepared by adapted sol gel method. In all compositions, pure single phase with cubic structure of BaSnO3 was identified by the X-ray diffraction (XRD) technique. Pure BaSnO3 gives a band gap energy of 3.25 eV which red shifted to 3.1, 3.12 and 3.13 eV after incorporation of (2% Fe, 2% Cu), (2% Fe, 4% Cu) and (2% Fe, 6% Cu) ions, respectively. The scanning electron microscope (SEM) images reflects that the Fe/Cu blends obstruct the grains growth of BaSnO3 and also influenced on the particles shape and porosity. The energy dispersive X-ray (EDX) maps confirmed the homogenous spatial distribution of Fe and Cu in the codoped BaSnO3 structure. The X-ray photoelectron spectroscopy (XPS) results of BaSn0.92Fe0.02Cu0.06O3 prove that Ba, Sn, O, Fe and Cu elements possess the oxidation states of +2, +4, −2, +3 and +1/+2, respectively. The magnetic performance of BaSnO3 structure exhibits a minor ferromagnetic loop with measured coercivity (Hc) of 330 Oe, magnetization (Ms) of 0.0023 emu/g and retentivity of 0.00077 emu/g. Interestingly, the addition of 6 wt% Cu (nonmagnetic dopant) plus 2 wt% Fe (magnetic dopant) strongly boosts the saturation magnetization value of BaSnO3 to 1.85 emu/g. The results open the door to tune the ferromagnetic order of BaSnO3 using nonmagnetic dopant to avoid the formation of magnetic impurities. The F-center exchange interaction and the bound magnetic polarons model were used to explain the measured room temperature ferromagnetism.

Room-Temperature Antisymmetric Magnetoresistance in Van Der Waals Ferromagnet Fe3GaTe2 Nanosheets.

Van der Waals (vdW) ferromagnetic materials have emerged as a promising platform for the development of 2D spintronic devices. However, studies to date are restricted to vdW ferromagnetic materials with low Curie temperature (Tc) and small magnetic anisotropy. Here, a chemical vapor transport method is developed to synthesize a high-quality room-temperature ferromagnet, Fe3GaTe2 (c-Fe3GaTe2), which boasts a high Tc = 356 K and large perpendicular magnetic anisotropy. Due to the planar symmetry breaking, an unconventional room-temperature antisymmetric magnetoresistance (MR) is first observed in c-Fe3GaTe2 devices with step features, manifesting as three distinctive states of high, intermediate, and low resistance with the sweeping magnetic field. Moreover, the modulation of the antisymmetric MR is demonstrated by controlling the height of the surface steps. This work provides new routes to achieve magnetic random storage and logic devices by utilizing the room-temperature thickness-controlled antisymmetric MR and further design room-temperature 2D spintronic devices based on the vdW ferromagnet c-Fe3GaTe2.

Thickness- and Field-Dependent Magnetic Domain Evolution in van der Waals Fe3GaTe2.

The discovery of room-temperature ferromagnetism in van der Waals (vdW) materials opens new avenues for exploring low-dimensional magnetism and its applications in spintronics. Recently, the observation of the room-temperature topological Hall effect in the vdW ferromagnet Fe3GaTe2 suggests the possible existence of room-temperature skyrmions, yet skyrmions have not been directly observed. In this study, real-space imaging was employed to investigate the domain evolution of the labyrinth and skyrmion structure. First, Néel-type skyrmions can be created at room temperature. In addition, the influence of flake thickness and external magnetic field (during field cooling) on both labyrinth domains and the skyrmion lattice is unveiled. Due to the competition between magnetic anisotropy and dipole interactions, the specimen thickness significantly influences the density of skyrmions. These findings demonstrate that Fe3GaTe2 can host room-temperature skyrmions of various sizes, opening up avenues for further study of magnetic topological textures at room temperature.

Distinct skyrmion phases at room temperature in two-dimensional ferromagnet Fe3GaTe2

Distinct skyrmion phases at room temperature hosted by one material offer additional degree of freedom for the design of topology-based compact and energetically-efficient spintronic devices. The field has been extended to low-dimensional magnets with the discovery of magnetism in two-dimensional van der Waals magnets. However, creating multiple skyrmion phases in 2D magnets, especially above room temperature, remains a major challenge. Here, we report the experimental observation of mixed-type skyrmions, exhibiting both Bloch and hybrid characteristics, in a room-temperature ferromagnet Fe3GaTe2. Analysis of the magnetic intensities under varied imaging conditions coupled with complementary simulations reveal that spontaneous Bloch skyrmions exist as the magnetic ground state with the coexistence of hybrid stripes domain, on account of the interplay between the dipolar interaction and the Dzyaloshinskii-Moriya interaction. Moreover, hybrid skyrmions are created and their coexisting phases with Bloch skyrmions exhibit considerably high thermostability, enduring up to 328 K. The findings open perspectives for 2D spintronic devices incorporating distinct skyrmion phases at room temperature.

Structural distortion and dynamical electron correlation driven enhanced ferromagnetism in Ni-doped two-dimensional Fe5GeTe2 beyond room temperature

Achieving beyond room-temperature ferromagnetism in two-dimensional (2D) magnets is immensely desirable for spintronic applications. Fe5GeTe2 is an exceptional van der Waals metallic ferromagnet due to its tunable physical properties and relatively higher Curie temperature ( TC ) than other 2D magnets. Using density functional theory combined with dynamical electron correlation and Monte Carlo simulations, we find the TC of (Fe 1−δ Ni δ)5 GeTe2 monolayer can increase up to ∼400 K at δ∼0.20 (δ: fractional occupation). Two specific Fe sublattices are identified to be the most energetically preferred sites to host Ni. Exchange interactions between particular Fe pairs play a dominating role in controlling TC , influenced by the dopant-induced structural distortions. Dynamical electron correlation induces site- and orbital-specific quasi-particle mass of Fe-d states with varying Ni concentrations. This work provides fundamental insights into 2D magnetism as an interplay of structural and electronic aspects and would guide to tailoring exciting magnetic phenomena in similar systems.

Enhanced catalytic degradation of organic dye by Sn1-xLaxO2 nanoparticles under UV light for wastewater treatment

Effectively eliminating dyes and heavy metals from wastewater, without secondary contamination and with easy recovery, is a significant challenge. To address this, SnO2-based photocatalysts were fabricated using a straightforward sol–gel method, aiming to achieve high-value reutilization and environmental protection. Utilizing XRD, FTIR, and HRTEM, the investigation has conclusively confirmed the emergence of nanoparticles (NPs) through rigorous analysis and observation techniques. Raman, XPS, and PL spectroscopy probed electronic, optical properties, and lattice defects, offering comprehensive insights into material characteristics. Specific BET surface areas were observed to be 17.72 and 39.64 m2/g for 0 % and 5 % La samples. The introduction of dopant La to the SnO2 lattice resulted in enhanced optical properties, demonstrated by a significant red shift. La-SnO2 nanoparticles demonstrated remarkable catalytic efficacy, degrading 94 % of RB dye solution under 60 min of UV light exposure. Even after four cycles, the catalytic degradation activity remained high at 87 %, showcasing excellent structural stability. Enhanced adsorption capacity and effective separation of electron-hole pairs under light contribute to this improvement. Moreover, the study delved into defect-based room temperature ferromagnetism (RTFM) by examining the formation of a novel network, such as La3+-O-Sn4+. The results highlight the potential of these composites doped photocatalysts as effective materials for degrading harmful organic pollutants in wastewater treatment and for their application in spintronic devices. The present study aims to characterize the structural, magnetic, and optical attributes of La-doped SnO2 nanoparticles.

Two-Dimensional Os2Se3 Nanosheet: A Ferroelectric Metal with Room-Temperature Ferromagnetism.

Two-dimensional (2D) ferroelectric metals (FEMs) possess intriguing characteristics, such as unconventional superconductivity and the nonlinear anomalous Hall effect. However, their occurrence is exceedingly rare due to mutual repulsion between ferroelectricity and metallicity. In addition, further incorporating other features like ferromagnetism into FEMs to enhance their functionalities poses a significantly greater challenge. Here, via first-principles calculations, we demonstrate a case of an FEM that features a coexistence of room-temperature ferromagnetism, ferroelectricity, and metallicity in a thermodynamically stable 2D Os2Se3. It presents a vertical electric polarization of 3.00 pC/m that exceeds those of most FEMs and a moderate polarization switching barrier of 0.22 eV per formula unit. Moreover, 2D Os2Se3 exhibits robust ferromagnetism (Curie temperature TC ≈ 527 K) and a sizable magnetic anisotropy energy (-30.87 meV per formula unit). Furthermore, highly magnetization-dependent electrical conductivity is revealed, indicative of strong magnetoelectric coupling. Berry curvature calculation suggests that the FEM might exhibit nontrivial band topology.

Intrinsic Room-Temperature Ferromagnetism in New Halide Perovskite AgCrX3 (X: F, Cl, Br, I) Using Ab Initio and Monte Carlo Simulations.

Herein, we present a detailed comparative study of the structural, elastic, electronic, and magnetic properties of a series of new halide perovskite AgCrX3 (X: F, Cl, Br, I) crystal structures using density functional theory, mean-field theory (MFT), and quantum Monte Carlo (MC) simulations. As demonstrated by the negative formation energy and Born-Huang stability criteria, the suggested perovskite compounds show potential stability in the cubic crystal structure. The materials are ductile because the Pugh's ratio is greater than 1.75, and the Cauchy pressure (C12-C44) is positive. The ground state magnetic moments of the compound were calculated as 3.70, 3.91, 3.92, and 3.91 μB for AgCrF3, AgCrCl3, AgCrBr3, and AgCrI3, respectively. The GGA + SOC computed spin-polarized electronic structures reveal ferromagnetism and confirm the metallic character in all of these compounds under consideration. These characteristics are robust under a ±3% strained lattice constant. Using relativistic pseudopotentials, the total energy is calculated, which yields that the single ion anisotropy is 0.004 meV and the z-axis is the hard-axis in the series of AgCrX3 (X: F, Cl, Br, and I) compounds. Further, to explore room-temperature intrinsic ferromagnetism, we considered ferromagnetic and antiferromagnetic interactions of the magnetic ions in the compounds by considering a supercell with 2 × 2 × 2 dimensions. The transition temperature is estimated by two models, namely, MFT and MC simulations. The calculated Curie temperatures using MC simulations are 518.35, 624.30, 517.94, and 497.28 K, with ±5% error for AgCrF3, AgCrCl3, AgCrBr3, and AgCrI3 compounds, respectively. Our results suggest that halide perovskite AgCrX3 compounds are promising materials for spintronic nanodevices at room temperature and provide new recommendations. For the first time, we report results for novel halide perovskite compounds based on Ag and Cr atoms.

Room temperature ferromagnetism in undoped and Fe doped Zn3P2 nanoparticles: Structural, optical and magnetic properties

In the current study, the structural, optical, and magnetic characteristics of Fe-doped Zn3P2 nanoparticles prepared by the solid-state reaction technique with various concentrations of Fe (x = 0.00, 0.02, 0.04, 0.06, and 0.08) were investigated. Studies using X-ray diffraction (XRD) verified that all of the produced samples had a tetragonal structure without any other phase, and that the lattice parameters increased (a = 8.090 Å, c = 11.421 Å to a = 8.120 Å, c = 11.499 Å) as the amount of dopant increased. The scanning electron microscopy (SEM) performed on the sample demonstrates that the grain size is almost spherical. The size of agglomerations slightly increases with increasing dopant concentration. The results of an energy dispersive X-ray analysis (EDAX) are almost exactly what was anticipated for the atomic weight ratios. The optical bandgap of the samples went from being 1.406 eV to being 1.453 eV when the dopant concentration was raised. When excited at wavelengths of 210 nm and 240 nm, rather than 307 nm, very intensity Photoluminescence (PL) emission spectra were detected in all of the samples. Vibrating sample magnetometer (VSM) verified that magnetic moment is found to increase (0.08829 emu/g to 0.23125 emu/g) with increase of dopant concentration from 0.02 to 0.08.

Profiles of oxygen and titanium point defects in ferromagnetic TiO2 films

Experimentally it is shown that without any oxygen manipulation for TiO2, a strong room temperature ferromagnetism could be expected only in ultra-thin films, with the ideal thickness below 100 nm. Both bulks and nano-powders of TiO2 are diamagnetic, indicating that the surface and its nano-sublayers play very important roles in tailoring the magnetic properties in this type of compound. To shed a new light on the defect-related magnetism in the typical case of anatase TiO2 surfaces, we have performed a series of quantum-mechanical calculations for TiO2 slabs containing Ti or O vacancies in different distances from the (001) surface. The lowest formation energies were obtained for the Ti vacancies in the first sub-surface layer and the O vacancies within the surface. The computed magnetic states reflect complicated structural relaxations of atoms influenced by both the surface and vacant atomic positions. O atoms cannot contribute much to magnetic moment when Ti vacancies are isolated and far from the surface. Ti vacancies in TiO2 are only metastable. The formation energy of Ti interstitials is lower than for Ti vacancies since high-temperature annealing, especially with a lot of O2 available that would fill up O-related defects, and as a result, eliminate most of Ti vacancies. Lower temperatures, less O2, and shorter exposure times may enable not only partial elimination of Ti vacancies but also can facilitate their diffusion into different states of aggregations. In the ferromagnetic films (i.e. thin films below 100 nm), it looks like that the O atoms are located closer to the Ti vacancies.

Introduction and Advancements in Room-Temperature Ferromagnetic Metal Oxide Semiconductors for Enhanced Photocatalytic Performance

Recent advancements in the field of room-temperature ferromagnetic metal oxide semiconductors (RTFMOS) have revealed their promising potential for enhancing photocatalytic performance. This review delves into the combined investigation of the photocatalytic and ferromagnetic properties at room temperature, with a particular focus on metal oxides like TiO2, which have emerged as pivotal materials in the fields of magnetism and environmental remediation. Despite extensive research efforts, the precise mechanism governing the interplay between ferromagnetism and photocatalysis in these materials remains only partially understood. Several crucial factors contributing to magnetism, such as oxygen vacancies and various metal dopants, have been identified. Numerous studies have highlighted the significant role of these factors in driving room-temperature ferromagnetism and photocatalytic activity in wide-bandgap metal oxides. However, establishing a direct correlation between magnetism, oxygen vacancies, dopant concentration, and photocatalysis has posed significant challenges. These RTFMOS hold immense potential to significantly boost photocatalytic efficiency, offering promising solutions for diverse environmental- and energy-related applications, including water purification, air pollution control, and solar energy conversion. This review aims to offer a comprehensive overview of recent advancements in understanding the magnetism and photocatalytic behavior of metal oxides. By synthesizing the latest findings, this study sheds light on the considerable promise of RTFMOS as effective photocatalysts, thus contributing to advancements in environmental remediation and related fields.

Induced Magnetization in Antiferromagnetic GdFeO3 by Nonmagnetic Titanium Substitution for Magnetic Switching and Storage Application

Room temperature ferromagnetism has been induced in antiferromagnetic GdFeO3 by substituting titanium at Gd site Gd1-xTixFeO3 (x=0.00 - 0.25). Perovskite GdFeO3 has been synthesized at lower temperature by chemical co-precipitation. Titanium substitution in gadolinium orthoferrite has transformed the perovskite phase to garnet phase confirmed by X-ray diffraction analysis. Tolerance factor of perovskite structure has been reduced from 0.81 to 0.78 for x=0.25 Ti substitution. Antiparallel G-type electron spins of GdFeO3 has been distorted by structural change induced due to titanium substitution. Ferromagnetism has been increased to 0.74 emu/g from 0.5 emu/g by titanium substitution. Retentivity and coercivity has been also increased from 0.005 emu/g to 0.28 emu/g and 27 Oe to 218 Oe respectively. The increase in magnitude of ferromagnetic transition with respect of temperature has been significantly observed by high temperature magnetization measurement. Present process is easy to induce room temperature ferromagnetism in antiferromagnetic GdFeO3 by distorting the structure at lower temperature by titanium substitution. The retentivity and coercivity produced at x=0.25 titanium substitution is useful for magnetic memory and switching application.

Highly Efficient Room-Temperature Spin-Orbit-Torque Switching in a Van der Waals Heterostructure of Topological Insulator and Ferromagnet.

All-Van der Waals (vdW)-material-based heterostructures with atomically sharp interfaces offer a versatile platform for high-performing spintronic functionalities at room temperature. One of the key components is vdW topological insulators (TIs), which can produce a strong spin-orbit-torque (SOT) through the spin-momentum locking of their topological surface state (TSS). However, the relatively low conductance of the TSS introduces a current leakage problem through the bulk states of the TI or the adjacent ferromagnetic metal layers, reducing the interfacial charge-to-spin conversion efficiency (qICS). Here, a vdW heterostructure is used consisting of atomically-thin layers of a bulk-insulating TI Sn-doped Bi1.1Sb0.9Te2S1 and a room-temperature ferromagnet Fe3GaTe2, to enhance the relative current ratio on the TSS up to ≈20%. The resulting qICS reaches ≈1.65 nm-1 and the critical current density Jc ≈0.9×106Acm-2 at 300 K, surpassing the performance of TI-based and heavy-metal-based SOT devices. These findings demonstrate that an all-vdW heterostructure with thickness optimization offers a promising platform for efficient current-controlled magnetization switching at room temperature.

Observation of room-temperature ferromagnetism in copper-based graphene induced by stress engineering

Two-dimensional (2D) room-temperature ferromagnetism is highly sought after for its great application potential but is challenged by chemical or magnetic structural instability. If room-temperature ferromagnetism can be realized in structurally stable 2D graphene, it will have a broad application prospect and market in flexible spintronics and wearable artificial intelligence. Although symmetry breaking such as vacancies, edges can introduce localized magnetic moments in intrinsically antimagnetic graphene, their weak coupling can only hold long-range ordering at low temperatures. Here, a robust ferromagnetic order has been observed in large-area graphene (centimeter scale) through mechanical folding and successive preprocesses of rapid cooling and heating method, where the Curie temperature of ∼6-layer graphene is close to 100 K and that of ∼10-layer graphene is above room temperature. We propose that the observed ferromagnetism is possibly attributed to the surface sp3-type bonds emergent in the structure phase transition caused by strain effects.

D0 ferromagnetic display of zirconia nanocrystallites and the impact of gold doping on their structural, optical, and magnetic properties

[Formula: see text] ferromagnetism is currently under extensive investigation as an alternative to transition metal-doped dilute magnetic semiconductors in the continuously evolving field of spintronics and optoelectronic applications. The literature contains numerous conflicting sources regarding its origin, specifically in materials such as oxides, making it a subject of ongoing controversy. This work mainly centers on the interplay among gold doping, oxygen concentration, and resulting changes in the structural, optical, and magnetic characteristics, with a specific focus on [Formula: see text] ferromagnetism and room temperature ferromagnetism in sol–gel synthesized zirconia nanocrystals. The powder samples crystallized in a mixed monoclinic-tetragonal phase. The weak absorbance band around 280[Formula: see text]nm and the O-1s peak in X-ray photoelectron spectroscopy provide insights into the metastable tetragonal phase’s stability, attributed to oxygen vacancies. The bandgap slightly increases from 4.6[Formula: see text]eV to 5.0[Formula: see text]eV due to the transformation from a tetragonal to a monoclinic phase. Magnetic studies reveal room-temperature ferromagnetism induced by oxygen vacancies in undoped zirconia, while a shift from ferromagnetic to paramagnetic behavior occurs in gold-infused zirconia samples.

Microwave graphitic nitrogen/boron ultradoping of graphene

Insufficient carrier concentration and lack of room temperature ferromagnetism in pristine graphene limit its dream applications in electronic and spintronic chips. While theoretical calculations have revealed that graphitic ultradoping can turn graphene into semiconducting and room temperature ferromagnetic, the exotic set of thermodynamic conditions needed for doping result in defects and functionalities in graphene which end up giving significant electronic scattering. We report our discovery of microwave ultradoping of graphene with N > 30%, B ~ 19%, and co-doping to form BCN phases (B5C73N22, B8C76N16, and B10C77N13). An unprecedented level of graphitic doping ~95% enhances carrier concentration up to ~9.2 × 1012 cm−2, keeping high electronic mobility ~9688 cm2 V−1s−1 intact, demonstrated by field effect transistor measurements. Room temperature ferromagnetic character with magnetization ~4.18 emug−1 is reported and is consistent with our DFT band structure calculations. This breakthrough research on tunable graphitic ultradoping of 2D materials opens new avenues for emerging multi-functional technological applications.

Strain engineering induced surfacial catalytic amorphous Ni3C with room temperature ferromagnetism for magnetic heating enhancement of overall water-splitting

Amorphous materials have been recognized as highly active electrocatalysts due to their abundant active sites stems from unsaturated chemical bonds. In addition, the application of alternating magnetic fields (AMF) to achieve magnetic heating effect has gradually become an important means to improve the performance of magnetic catalysts. Here, we have successfully realized the surfacial amorphization of confined Ni3C nanoparticles by using interfacial strain engineering. As expected, the surfacial amorphized Ni3C nanoparticles exhibit remarkable properties in electrochemical water-splitting. More importantly, magnetic measurements show that the surfacial amorphized Ni3C nanoparticles have room temperature ferromagnetism, which is consistent with our theoretical calculation results. Accordingly, under AMF stimulation, its overall water-splitting performance is further greatly improved as the result of magnetic heating effect associated with Néel relaxation. This work provides a new strategy for the development of highly efficient surfacial amorphized catalysts, and promotes the application of magnetothermal technology in amorphous catalysis.

Structure, room-temperature ferromagnetism and its mechanism in zirconia nanotubes prepared by anodization

Defect-induced room-temperature ferromagnetism has important potential applications in data storage, sensors and spintronic devices. The anode ZrO2 nanotube film has the characteristics of simple preparation and abundant surface defects. In this work, highly ordered and independent of each other ZrO2 nanotubes with pore sizes of 31 ∼ 49 nm were successfully prepared by anodization. Interestingly, obvious room temperature ferromagnetism and magnetic anisotropy were observed in these prepared ZrO2 nanotube films, magnetism with out-of-plane direction significantly greater than that with in-plane direction. Among them, the ZrO2 nanotube film with a pore size of 40.23 nm was prepared the anodization voltage of 30 V, exhibiting an out-of-plane saturation magnetization of approximately 0.635 emu/cm3 and a coercivity of 11 Oe. It is found that the room temperature ferromagnetism is related to the special independent tubular structure and oxygen vacancy defects. From the perspective of hydrogen-like impurities and localized state, the coupling mechanism of oxygen vacancies trapped electrons is explained in this work, and these phenomena of room temperature ferromagnetism, magnetic anisotropy and higher Curie temperature are well interpreted. Our work not only improves the understanding of magnetic properties in tubular-structure materials but also expands the application in spintronic devices.

Turning Nonmagnetic Two-Dimensional Molybdenum Disulfides into Room-Temperature Ferromagnets by the Synergistic Effect of Lattice Stretching and Charge Injection.

Exploring two-dimensional (2D) room-temperature magnetic materials in the field of 2D spintronics remains a formidable challenge. The vast array of nonmagnetic 2D materials provides abundant resources for exploration, but the strategy to convert them into intrinsic room-temperature magnets remains elusive. To address this challenge, we present a general strategy based on surface halogenation for the transition from nonmagnetism to intrinsic room-temperature ferromagnetism in 2D MoS2 based on first-principles calculations. The derived 2D halogenated MoS2 are half-semimetals with a high Curie temperature (TC) of 430-589 K and excellent stability. In-depth mechanistic studies revealed that this marvelous nonmagnetism-to-ferromagnetism transition originates from the modulation of the splitting as well as the occupation of the Mo d orbitals by the synergy of lattice stretching and charge injection induced by the surface halogenation. This work establishes a promising route for exploring 2D room-temperature magnetic materials from the abundant pool of 2D nonmagnetic counterparts.