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This paper aims to investigate the behavior of LiMgN half-Heusler (HH) semiconductor doped by transition metals (TM  =  Mn, Fe, Co and Ni). HHs belong to the F 4 ̄ 3 m space group (No. 216) and have a zinc blende structure that can be described by the chemical symbol XYZ. The research methodology utilized in this investigation involves theoretical analysis based on the principles of density functional theory (DFT). The studied LiMg 0. 9 5 TM 0. 0 5 N alloy displayed the half-metallicity behavior when TM  =  Fe, Co and Ni. Hence, these systems could be a promising candidate in spintronic application thanks to their ferromagnetism. The principal contribution to magnetism in the full LiMg 0. 9 5 TM 0. 0 5 N alloys comes from the Mn, Fe, Co and Ni doping. The partial magnetic moments of these elements are significantly greater than the combined partial magnetic moments of Li, Mg and N. When comparing LiMg 0. 9 5 Mn 0. 0 5 N to LiMg 0. 9 5 Fe 0. 0 5 N, 5Co 0. 0 5 N and LiMg 0. 9 5 Ni 0. 0 5 N, it is important to note that the exchange splitting energy Δ (e + , e −) TM associated to their spin up and spin down were discussed. The variation of Mn(3d) in relation to ( e + , e − ) is larger than that of Fe, Co and Ni. Therefore, Δ (e + , e −) Mn > Δ (e + , e −) Fe > Δ (e + , e −) Co > Δ (e + , e −) Ni . Furthermore, there is a correlation between the magnetic moment and electronegativity trend of the TM dopant. Specially, the electronegativity trend ( χ TM ) is well matched with the total spin moment trend, where χ Ni > χ Co > χ Fe > χ Mn . [ABSTRACT FROM AUTHOR]

Nano-size spinel ferrite CoFe2O4 (CFO), ferroelectric BaTiO3 (BTO), and their nanocomposites BTO@CFO (BTO nanoparticles are added during the synthesis of CFO) and CFO@BTO (CFO nanoparticles are added during the synthesis of BTO) were synthesized using a combination of chemical co-precipitation and sol–gel routes, respectively. The phase formation and crystallinity of the bare CFO and BTO and their nanocomposites were verified via x-ray diffraction (XRD) patterns. High-resolution transmission electron microscopy (HRTEM) revealed the formation of the nanocomposites. Magnetization measurements confirmed the ferromagnetic behavior of all the samples except BTO, in which superposition of a weak ferromagnetic and diamagnetic response occurred due to its nanostructure. Magnetization versus temperature (M–T plot) measurements showed an anomaly near the ferroelectric-to-paraelectric phase transition of BTO. Also, the dielectric constant (ε′) and loss tangent (tanδ) with respect to frequency (102–106 Hz) and temperature (300–700 K) were examined. The ε′–T curve of the nanocomposites exhibited an anomaly at the same temperature as observed in the M–T plot, indicating the inherent magnetoelectric coupling in the nanocomposites. The energy storage properties of BTO and the nanocomposites were examined via P–E loop analysis and confirmed that the CFO@BTO sample exhibits maximum energy storage efficiency. [ABSTRACT FROM AUTHOR]

Integrating two-dimensional layered supercell (LSC) oxides and plasmonic Au nanostructures into one hybrid framework can open up multifunctionality tuning into a new level. In this work, Bi-based LSCs Bi3Fe2Mn2Ox and Bi2WO6 incorporated with secondary plasmonic Au and/or ferromagnetic La0.7Sr0.3MnO3 phases have been grown via pulsed laser deposition (PLD). Microstructural characterization results show the highly epitaxy film quality and distinct LSC structures despite the incorporated secondary phases. The nanocomposite films exhibit multiferroic and plasmonic responses due to the multi-phase coupling. This work provides a new approach of integrating self-assembled LSC-metal/oxide nanocomposite thin films for future multiferroics and spintronics device applications. [ABSTRACT FROM AUTHOR]

This work comprehensively studies the electronic, structural, optical, thermodynamic and thermoelectric properties of the Co2CrBi Heusler compound for both ferromagnetic and antiferromagnetic phases. The calculation is based on the Full-potential Linearized Augmented Plane-Wave (FP-LAPW) method by using the "WIEN2k" code, with the Generalized Gradient Approximation (PBE-GGA) for the exchange–correlation potential. The calculations reveal that Co2CrBi exhibits metallic behavior due to the spin polarization at the Fermi level. Further calculations were performed using GGA + SOC + U and hybrid functional HSE06 approximations to confirm this metallic nature. The antiferromagnetic phase is more stable than the ferromagnetic phase, although it cannot be regarded as a hard material. Various properties, including electron energy loss, refractive index, extinction coefficient, optical conductivity, Seebeck coefficient, electrical conductivity, and thermal conductivity are also computed and discussed for both ferromagnetic and antiferromagnetic phases. Additionally, this investigation is extended to encompass the unexplored properties of Co2CrBi, including both thermodynamic and thermoelectric. [ABSTRACT FROM AUTHOR]

For the 2D metal‐free carbon catalysts, the atomic coplanar architecture enables a large number of pz orbitals to overlap laterally, thus forming π‐electron delocalization, and the delocalization degree of the central atom dominates the catalytic activity. Herein, designing sulfur‐doped defect‐rich graphitic carbon nitride (S‐Nv‐C3N4) materials as a model, we propose a strategy to promote localized electron polarization by enhancing the ferromagnetism of ultra‐thin 2D carbon nitride nanosheets. The introduction of sulfur (S) further promotes localized ferromagnetic coupling, thereby inducing long‐range ferromagnetic ordering and accelerating the electron interface transport. Meanwhile, the hybridization of sulfur atoms breaks the symmetry and integrity of the unit structure, promotes electron enrichment and stimulating electron delocalization at the active site. This optimization enhances the *OOH desorption, providing a favorable kinetic pathway for the production of hydrogen peroxide (H2O2). Consequently, S‐Nv‐C3N4 exhibits high selectivity (>95 %) and achieves a superb H2O2 production rate, approaching 4374.8 ppm during continuous electrolysis over 300 hour. According to theoretical calculation and in situ spectroscopy, the ortho‐S configuration can provide ferromagnetic perturbation in carbon active centers, leading to the electron delocalization, which optimizes the OOH* adsorption during the catalytic process. [ABSTRACT FROM AUTHOR]

The degaussing process is crucial for ensuring magnetic protection in ships. It involves the application of oscillating and attenuating magnetic fields to eliminate residual magnetism in the ship's structure. However, this process can lead to the generation of distorted magnetic fields within the ship's cabin, posing a potential threat to electronic equipment performance. Therefore, it is essential to have a comprehensive understanding of the dynamic magnetic field response in ship structures to develop effective degaussing systems. To address this need, this paper proposes an eddy current model for analyzing the dynamic magnetic field response in ferromagnetic metal structures. This model focuses on the role of eddy currents in shaping the magnetic field response and provides valuable insights into the underlying mechanisms. Using the proposed eddy current model, the effects of key system parameters such as thickness, conductivity, and the length-scale of the ship structure can be analytically investigated. This analysis helps in understanding how these parameters influence the dynamic magnetic field response and aids in the design and optimization of degaussing systems. The effectiveness and applicability of the proposed eddy current model are demonstrated through comprehensive investigations involving two simulation cases of varying complexity. The model accurately predicts the changing trends of the dynamic magnetic field response, as confirmed through finite element simulations. This validation highlights the model's ability to reproduce simulation results accurately and its potential as a powerful tool for analyzing and optimizing dynamic magnetic field responses. In summary, the proposed eddy current model represents a significant advancement in the field. It provides a valuable theoretical framework for understanding and analyzing the dynamic magnetic field response in ferromagnetic metal structures. By offering insights into the underlying mechanisms and the influence of key parameters, this research contributes to the development of improved degaussing systems and enhances the overall magnetic protection capabilities of ships. [ABSTRACT FROM AUTHOR]

Currently, intercalation has become an effective way to modify the fundamental properties of two-dimensional (2D) van der Waals (vdW) materials. Using density functional theory, we systematically investigated the structures and electronic and magnetic properties of bilayer transition metal dichalcogenides (TMDs) intercalated with 3d TM atoms (TM = Sc–Ni), TM@BL_MS2 (M = Mo, V). Our results demonstrate that all the studied TM@BL_MS2s are of high stability, with large binding energies and high diffusion barriers of TM atoms. Interestingly, most TM@BL_MoS2s and TM@BL_VS2s are found to be stable ferromagnets. Among them, TM@BL_MoS2s (TM = Sc, Ti, Fe, Co) are ferromagnetic metals, TM@BL_MoS2 (TM = V, Cr) and TM@BL_VS2 (TM = Sc, V) are ferromagnetic half-metals, and the remaining systems are found to be ferromagnetic semiconductors. Exceptions are found for Ni@BL_MoS2 and Cr@BL_VS2, which are nonmagnetic semiconductors and ferrimagnetic half-metals, respectively. Further investigations reveal that the electromagnetic properties of TM@BL_MoS2 are significantly influenced by the concentration of intercalated TM atoms. Our study demonstrates that TM atom intercalation is an effective approach for manipulating the electromagnetic properties of two-dimensional materials, facilitating their potential applications in spintronic devices. [ABSTRACT FROM AUTHOR]

Context: Li2VMgO6, Li2NbMgO6, and Li2TaMgO6 double perovskite compounds were energetically the most stable in the FM phase. The lattice constants were 7.63 Å, 7.94 Å, and 7.95 Å, and the Curie temperatures were 910.451 K, 930.739 K, and 1258.821 K, respectively. The wide bandgap semiconductor characters were provided in the GGA-PBE methods as 2.139 eV, 4.209 eV, and 5.007 eV, respectively. This wide band gap semiconductor state in the majority carriers and the metallic state in the minority states made these double perovskites true half-metallic ferromagnetics. The bulk modulus obtained in the ground state calculations and the values obtained from thermodynamic calculations were relatively close. Debye temperatures in the initial state conditions were 747 K, 685.13 K, and 587.77 K, respectively. The total magnetic moment values were calculated as 3.00 µB/f.u. The most significant contribution to this value came from oxygen atoms. Methods: The theoretical calculations of Li2VMgO6, Li2NbMgO6, and Li2TaMgO6 double perovskite alloys were performed using the WIEN2k program developed by Blaha et al. The electronic calculations were made with GGA-PBE, GGA + mBJ, and GGA + U approximations in the space number 225 and the Fm-3 m symmetry group. The thermodynamic calculations were performed using Gibbs2. In thermodynamic calculations, temperature increases were determined as 100 K and temperature values were increased from 0 to 1200 K. [ABSTRACT FROM AUTHOR]

Cr-doped In2O3 nanoparticles have been prepared via combustion method. Glycine fuel was used for the synthesis. The prepared compounds were evaluated for their potential as a dilute magnetic semiconductor (DMS) by studying their magnetic properties. X-ray diffraction (XRD) pattern was studied to identify the crystal structure of pristine and doped In2O3 compounds. Morphology and particle size of the compounds have been estimated using transmission electron microscope (TEM). Valence state of the elements was found out by making use of X-ray photoelectron spectroscopy (XPS) technique. Electrical resistivity has been measured which displayed higher resistance value for doped samples. Magnetisation studied with vibrating sample magnetometer (VSM) at room temperature displayed weak ferromagnetism in the doped samples. The measurements at 50 K displayed antiferromagnetic/paramagnetic alignment. The importance of preparative method, nano-size, room-temperature defects and oxygen vacancies in regulating magnetism in DMS has been discussed. [ABSTRACT FROM AUTHOR]

Magnesium-doped nickel ferrite nanoparticles with the chemical composition (Ni1−xMgxFe2O4, x = 0.00, 0.20, and 0.40) have been prepared by a modified sol–gel citrate method. Structural analysis was carried out through x-ray diffractograms (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The spherical-shaped morphology of the prepared nanoparticles has been confirmed by field-emission scanning electron microscopy (FESEM). The energy dispersive x-ray (EDX) analysis confirmed the presence of elements (Ni, Mg, Fe, and O) in the prepared compositions. The distribution of cations over tetrahedral and octahedral sites has been confirmed by Rietveld refinement using FullProf software. The phenomena of Maxwell–Wagner polarization is exhibited in the dielectric measurements. Cole–Cole plots showed that the net grain (Rg) and grain boundary resistance (Rgb) values are decreasing for the maximum concentration of Mg2+ ions in the nickel ferrites. Almost 96% deductions in the tangent loss values have been observed at high temperatures with the increasing concentration of Mg2+ ions in the nickel ferrites. Fitting of AC conductivity was carried out using the Jonscher Power Law function. The net magnetization saturation values also decreased from 27.7 emu/g to 16.7 emu/g upon the doping of Mg2+ ions in the pure nickel ferrites. These properties are all desired for materials working under high-frequency applications. [ABSTRACT FROM AUTHOR]

The oxygen vacancy properties are significant, creating ferromagnetic properties of material in metal oxide systems like dilute magnetic semiconductors. An aqueous sol-gel method has been used in the present study to synthesize non-stoichiometry BaTiO3-x polycrystalline. In an attempt of examining the oxygen deficiency consequences on the magnetic properties, the gel samples were sintered (1000◦C) at various times (6, 12, 18, and 24 hours) under a vacuum environment. This study employs an X-ray diffraction apparatus in terms of characterizing segments and structures of the samples. It also investigates morphology and element distribution on the surface of the samples exploiting an Electron microscope where Energy dispersive spectroscopy is supplied. For the purpose of characterizing the magnetic properties of the samples, it applies vibrating sample magnetometers. The chemical state of the element and its corresponding bond to other elements was identified using X-ray photoelectron spectroscopy. Single-phase compounds were observed. The crystal system is tetragonal, but the crystal parameters are different. Increase sintering time leads to increase crystallite size and decrease in micro strain. Moreover, sintering in a vacuum environment results in oxygen deficiency and leads to the atomic ratio of Ba/Ti change as the sintering time increases. The Ba/Ti ratio change affects the transformation from diamagnetic to ferromagnetic-like. The elements (Ba, Ti and O) chemical state is shown and its bonding to the corresponding element along with the X-ray photoelectron spectroscopy pattern of the BTX2 sample. The element of oxygen binds to Ti and Ba while Ba element exists in two chemical states.

Using the first-principles calculations, we have investigated the structural, electronic, and magnetic properties of the two-dimensional Janus MnSX (X= Cl, Br, I) monolayers. The dynamical stability for the 2D Janus monolayers has been confirmed by phonon spectrum calculation. Also, all manganese sulfide halide monolayers show half-metal with 100% spin polarization and a wide half-metallic gap. The noncollinear DFT calculations indicate that the two-dimensional Janus monolayers are ferromagnetically ordered systems and the preferred direction of magnetization lies in-plane of Janus manganese sulfide halide monolayers. The magnetic anisotropy energy increases from MnSCl to MnSI, related to the strong spin-orbit coupling at the I atom and the increased asymmetry between the sulfide and halide planes. The dispersion relation of magnetic excited states is obtained by applying the linear order Holstein–Primakoff transformation to the anisotropic Heisenberg Hamiltonian. We estimated Curie temperature for the monolayers by a self-consistent calculation of magnetization as a function of temperature. Our study presents a new class of 2D magnetic materials for future spintronics and valleytronics.

Two-dimensional (2D) ferromagnetic semiconductors (FM SCs) provide an ideal platform for the development of quantum information technology in nanoscale devices. However, many developed 2D FM materials present a very low Curie temperature (TC), greatly limiting their application in spintronic devices. In this work, we predict two stable 2D transition metal chalcogenides, V3Se3X2 (X = S, Te) monolayers, by using first-principles calculations. Our results show that the V3Se3Te2 monolayer is a robust bipolar magnetic SC with a moderate bandgap of 0.53 eV, while V3Se3S2 is a direct band-gap FM SC with a bandgap of 0.59 eV. Interestingly, the ferromagnetisms of both monolayers are robust due to the V–S/Se/Te–V superexchange interaction, and TCs are about 406 K and 301 K, respectively. Applying biaxial strains, the FM SC to antiferromagnetic (AFM) SC transition is revealed at 5% and 3% of biaxial tensile strain. In addition, their high mechanical, dynamical, and thermal stabilities are further verified by phonon dispersion calculations and ab initio molecular dynamics (AIMD) calculations. Their outstanding attributes render the V3Se3Y2 (Y = S, Te) monolayers promising candidates as 2D FM SCs for a wide range of applications. [ABSTRACT FROM AUTHOR]

Bismuth ferrite (BiFeO3) nanoparticles were synthesized using sol‐gel method and annealed at 450 °C, 550 °C, 650 °C, and 750 °C for 2 hours. The role of annealing temperature on structural, optical, magnetic, and dielectric properties of BiFeO3 nanoparticles was studied. XRD patterns of BiFeO3 nanoparticles confirm the rhombohedral structure with a mean crystallite size of 40 nm. The optical bandgap of the BiFeO3 nanoparticles increased from 1.9 eV to 2.02 eV with annealing temperature. From photoluminescence spectra, it was observed that the BiFeO3 nanoparticles showed a clear emission peak at 565 nm and its intensity decreased with annealing temperature. Magnetic properties of the BiFeO3 nanoparticles were studied at room temperature and different magnetic behaviours were found in BiFeO3 nanoparticles. The BiFeO3 nanoparticles exhibited ferromagnetism at low annealing temperatures and diamagnetic nature at high annealing temperatures. The AC conductivity studies showed that BiFeO3 nanoparticles possess a dielectric constant of 170 with the least dielectric loss. The BiFeO3 nanoparticles annealed at 750 °C were studied for photocatalytic properties and showed good photocatalytic activity in the visible region. A prominent absorption peak at 663 nm in absorption spectra due to MB and it confirm the utility of BFO as photocatalyst applications. [ABSTRACT FROM AUTHOR]

Co–Mo alloy clusters with extended solubility of Mo in hcp Co were produced by inert gas condensation (IGC). While the equilibrium solubility of Mo in hexagonal close-packed (hcp) Co is on the order of 1 atomic percent, the non-equilibrium aspects of IGC resulted in ~ 18 atomic percent Mo dissolved in hcp Co. The extended solid solutions and hcp structure were observed across all of the processing conditions, which included variation of sputtering power and aperture size. There was, however, variation of nanoparticle size and magnetic behavior with processing parameters. The Co(Mo) nanoparticles were ferromagnetic at room temperature. Coercivities of the nanoparticles produced with a 2.5-mm aperture were independent of sputtering power and significantly higher than those of the nanoparticles produced with a 7-mm aperture. The coercivities of the nanoparticles produced with a 7-mm aperture were slightly power-dependent. Overall, there appeared to be a relationship between coercivity and nanoparticle size. [ABSTRACT FROM AUTHOR]

A sol-gel method was employed to synthesize phase-pure (1-x)BiFeO3-xBi(Mn0.5Ti0.5)O3 (abbreviated as BFO-xBMT, x = 0–0.10) multiferroic ferrites. The investigation focused on the structure, optical, and magnetic properties, and their dependence on composition. X-ray diffraction analysis (XRD) revealed a single phase rhombohedral structure for BiFeO3 (BFO), with distinct double peaks (104)/(110) and (006)/(202) at diffraction angles 2θ ∼ 32.0° and 39.5°. As the content of Bi(Mn0.5Ti0.5)O3 (BMT) increased, a structural transition from rhombohedral (R3c) to pseudo-cubic (Pm3m) phase was observed. Doping with BMT led to a decrease in particle size. The band gap (Eg) of BFO-xBMT materials exhibited a slight increase from 1.99 eV in BFO to 2.18 eV in the BFO-0.10BMT composition. The introduction of BMT resulted in a significantly enhanced room temperature ferromagnetism in BiFeO3, with the maximum magnetic moment doubling to around 5.7 emu/g for the BFO-0.04BMT solid solution. This improvement is attributed to the addition of BMT inducing intrinsic strain in the crystal lattice, suppressing the intrinsic helical spin structure of BFO, and thus enhancing its latent magnetic potential. The research demonstrated the substantial influence of BMT perovskite on the structure, optical, and magnetic properties of BFO materials. Overall, the results suggest that the BFO-xBMT multiferroic ferrites with optimal composition hold promise for use in multifunctional devices. [ABSTRACT FROM AUTHOR]

This study examines the physical characteristics of Co2Te3O8 in the spiroffite structure using an ab initio approach. The optimization of the Co2Te3O8 structure, in both nonmagnetic and magnetic states, indicates that the magnetic state is more stable than the non-magnetic one. Thermodynamic properties under various temperatures and pressures, calculated via the quasi-harmonic approximation, reveal that the specific heat capacity of spiroffite Co2Te3O8 conforms to the Debye model and satisfies the Dulong and Petit limits. The electrical, magnetic, and optical properties of Co2Te3O8 are investigated using the GGA and TB-mBJ approximations. Analysis of the density of states and the band structure indicates that spiroffite Co2Te3O8 exhibits semiconductor characteristics in both the spin up and spin down channels. The study is extended to apply hydrostatic pressure to assess the electronic and magnetic properties of both unstrained and strained structures of Co2Te3O8. It is found that within the investigated pressure range (0–15 GPa), no structural changes are observed. Furthermore, a slight decrease in the spin up gap is noted, while no appreciable changes are observed in the spin down gap. Moreover, the investigation into the spin-polarized thermoelectric properties of the material reveals that it achieves a high figure of merit, approximately 0.99, across broad temperature spectra. This performance highlights its suitability as a candidate for thermoelectric power generation. Finally, optical properties calculations on spiroffite Co2Te3O8 reveal efficient absorption in the ultraviolet region. [ABSTRACT FROM AUTHOR]

Exploring magnetic order in nonferromagnetic substances, such as CuO:ZnO, becomes especially attractive when introducing defect states through nonmagnetic ion doping. In this study, we delved into the impact of Yb doping on the structural, morphological, optical, and magnetic properties of CuO:ZnO. The Yb doped CuO:ZnO was prepared with different Yb concentrations (x = 0.00–20 %) via the temperature-assisted co-precipitation method. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, and vibrating sample magnetometer (VSM) were used to investigate the structural, morphological, optical, and magnetic properties of Yb doped CuO:ZnO nanocomposites. The incorporation of Yb in CuO:ZnO nanocomposites leads to a notable shift of the characteristic XRD peaks of CuO and ZnO to lower angles, accompanied by an increase in the lattice parameters. UV–visible absorption spectroscopy shows an overall decrease in the optical band gap energy of ZnO as the Yb defect level increases. FE-SEM studies revealed the transformation of spherical structures into agglomerated non-spherical structures upon the introduction of Yb ions into CuO:ZnO nanocomposites. According to XPS data, the predominant valences of Yb-doped CuO:ZnO nanocomposites are Zn2+, Cu2+, and Yb3+. One noteworthy observation from the XPS results is that, in comparison to the intensity of O L or O ad peaks, the intensity of O V (Oxygen vacancy) defect peak increases when the Yb impurity concentration increases. Magnetic measurements demonstrated a diamagnetic order in pure ZnO, which converts to a ferromagnetic order with the incorporation of Yb defect states. The ferromagnetic properties of the Yb-doped CuO:ZnO nanocomposite can be ascribed to the exchange interaction of Yb3+ ions with defect states (Oxygen Vacancy) in ZnO and CuO. [ABSTRACT FROM AUTHOR]

This study examines the physical characteristics of Co2Te3O8 in the spiroffite structure using an ab initio approach. The optimization of the Co2Te3O8 structure, in both nonmagnetic and magnetic states, indicates that the magnetic state is more stable than the non-magnetic one. Thermodynamic properties under various temperatures and pressures, calculated via the quasi-harmonic approximation, reveal that the specific heat capacity of spiroffite Co2Te3O8 conforms to the Debye model and satisfies the Dulong and Petit limits. The electrical, magnetic, and optical properties of Co2Te3O8 are investigated using the GGA and TB-mBJ approximations. Analysis of the density of states and the band structure indicates that spiroffite Co2Te3O8 exhibits semiconductor characteristics in both the spin up and spin down channels. The study is extended to apply hydrostatic pressure to assess the electronic and magnetic properties of both unstrained and strained structures of Co2Te3O8. It is found that within the investigated pressure range (0–15 GPa), no structural changes are observed. Furthermore, a slight decrease in the spin up gap is noted, while no appreciable changes are observed in the spin down gap. Moreover, the investigation into the spin-polarized thermoelectric properties of the material reveals that it achieves a high figure of merit, approximately 0.99, across broad temperature spectra. This performance highlights its suitability as a candidate for thermoelectric power generation. Finally, optical properties calculations on spiroffite Co2Te3O8 reveal efficient absorption in the ultraviolet region. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This paper explores a newly created double perovskite substance named Sr2CrMnO6 (SCMO), produced using a gel combustion method. The research delves into the material's structural, optical, and magnetic characteristics. The material's purity and the development of a monoclinic structure with space group P21/n1 (#14) were verified using Rietveld refinement of the X-ray diffraction pattern. The material's band gap, determined to be 2.5 eV through UV-Vis spectroscopy and Tauc plot analysis, indicates its potential for optoelectronic applications. At room temperature, SCMO displays paramagnetic behavior and a ferromagnetic Curie temperature of approximately 250 K, suggesting its suitability for applications in low-temperature spintronics. [ABSTRACT FROM AUTHOR]

Realizing the rational control of two-dimensional valleytronics is appealing for potential applications in valleytronic devices. Using density functional theory method, we systematically study the magnetoelectronic coupling properties in ferrovalley/ferroelectricity van der Waals (vdW) heterostructure, ScI2/Ga2STe2. Interestingly, an on/off transition of the valley nature is found for this multiferroic ScI2/Ga2STe2 heterostructure. Under the Ga2STe2-P↑ polarization state, the heterostructure shows a ferromagnetic (FM) semiconducting feature with valley polarization, while it turns out to be FM metal when the ferroelectric (FE) polarization is switched to Ga2STe2-P↓; therefore, a switchable valleytronic device can be realized by altering the FE polarization direction. Furthermore, it is found that such switchable valleytronic behaviors of the ScI2/Ga2STe2 heterostructure can be modulated by applying biaxial strains for both FE polarization directions. The research of nonvolatile electrical control of valley splitting in the two-dimensional ScI2/Ga2STe2 multiferroic heterostructure provides a way for designing all-in-one valleytronic devices. [ABSTRACT FROM AUTHOR]

The temperature-dependent magnetic susceptibility combined with first-principle calculations was conducted to unravel the magnetic structure and the magnetic interaction of the laminar structure of manganese diboride (MnB2). MnB2 showed weak ferromagnetic, antiferromagnetic, and paramagnetic behavior with increased temperature. Its weak ferromagnetic property below 135.6 K Curie temperature (TC) originated from the spin canting antiferromagnetic magnetic structure. The exotic kink of temperature-dependent magnetic susceptibility at 330 K Néel temperature (TN) correlated with the transition from antiferromagnetic to paramagnetic structure. First-principle calculation show that the antiferromagnetic ordering show lower energy, and suggest a canting anti-ferromagnetic ordering for its ferromagnetic behavior. The peculiar magnetic behavior of MnB2 may be due to the insertion of the honeycomb boron layers into the host matrix of manganese atoms. The honeycomb boron layers played a key role in the exchange between two manganese layers. This study resolved the longstanding puzzle of the magnetic structure of MnB2 and provided a typical laminar magnetic structure prototype. [ABSTRACT FROM AUTHOR]

Second‐order topological insulators (SOTIs) in 2D materials have attracted significant research interest. Recent theoretical predictions suggest that SOTIs can be achievable in 2D magnetic systems, especially within ferromagnetic (FM) materials. Yet, the quest for suitable 2D antiferromagnetic (AFM) materials capable of hosting magnetic SOTIs remains a challenge. Herein, utilizing first‐principles calculations and theoretical analysis, 2D CrSBr is proposed, including monolayer and bilayer forms, as a promising candidate for a magnetic high‐order topological insulator. The monolayer exhibits a FM ground state and features quantized fractional corner charge in its spin‐up channel in the absence of spin–orbital coupling (SOC), yielding fully spin‐polarized corner states. Intriguingly, the bilayer form adopts an AFM ground state while retaining the SOTI properties, with quantized corner charge in both spin channels. Remarkably, the SOTI properties in both monolayer and bilayer structures remain robust against the influence of SOC and symmetry‐breaking perturbations. The work not only identifies a tangible material for realizing 2D magnetic SOTIs, encompassing both FM and AFM phases, but also offers a path to explore the distinctive characteristics of SOTIs merged with magnetism. [ABSTRACT FROM AUTHOR]

The current paper reports on the quantification of the effect of magnetic fields on the mechanical performance of ferromagnetic nanocomposites in situ during basic standard tensile testing. The research investigates altering the basic mechanical properties (modulus and strength) via the application of a contact-less magnetic field as a primary attempt for a future composites strengthening mechanism. The nanocomposite specimens were fabricated using filament-based 3D printing and were comprised of ferromagnetic nanoparticle-embedded thermoplastic polymers. The nanoparticles were iron particles dispersed at 21 wt.% (10.2 Vol.%) inside a polylactic acid (PLA) polymer, characterised utilising optical microscopy and 3D X-ray computed tomography. The magnetic field was stationary and produced using permanent neodymium round-shaped magnets available at two field strengths below 1 Tesla. The 3D printing was a MakerBot Replicator machine operating based upon a fused deposition method, which utilised 1.75 mm-diameter filaments made of iron particle-based PLA composites. The magnetic field-equipped tensile tests were accompanied by a real-time digital image correlation technique for localized strain measurements across the specimens at a 10-micron pixel resolution. It was observed that the lateral magnetic field induces a slight Poisson effect on the development of extrinsic strain across the length of the tensile specimens. However, the effect reasonably interferes with the evolution of strain fields via the introduction of localised compressive strains attributed to accumulated magnetic polarisation at the magnetic particles on an extrinsic scale. The theory overestimated the moduli by a factor of approximately 3.1. To enhance the accuracy of its solutions for 3D-printed specimens, it is necessary to incorporate pore considerations into the theoretical derivations. Additionally, a modest 10% increase in ultimate tensile strength was observed during tensile loading. This finding suggests that field-assisted strengthening can be effective for as-received 3D-printed magnetic composites in their solidified state, provided that the material and field are optimally designed and implemented. This approach could propose a viable method for remote field tailoring to strengthen the material by mitigating defects induced during the 3D printing process. [ABSTRACT FROM AUTHOR]

Objective: Public exposure to radiofrequency (RF) fields from fifth generation (5G) and other sources is known to be below human exposure limits. The interaction of RF fields with the human body has been widely documented, with tissue heating being the primary consequence for RF fields above 100 kHz. This study aimed to reveal possible harm to orthodontic patients associated with 5G electromagnetic waves. The possibility of individuals with orthodontic appliances (metallic braces, porcelain braces, thermoplastic appliances) being more affected by 5G was investigated. Methods: Sixty extracted human teeth were divided into 5 groups. Different types of brackets, arch, and ligature wires were applied to each group. Each group was exposed to 5G electromagnetic waves (3.6 GHz of frequency) for 60 minutes. Temperature measurements were made inside the canine root canals and in saline solution. Results: Exposure to a 5G electromagnetic field increased the temperatures of the root canal of the tooth and sodium chloride (NaCl) solution surrounding samples. Temperature increase in the canals were as follows; metal self-ligating braces > mini metal braces > porcelain braces > clear aligner > control. The temperature change in the NaCl solution at the 60th minute was close to each other in the self-ligating braces and mini metal braces groups. The temperature rise of the NaCl solution in the control group was also minimal. Conclusion: The hypothesis that orthodontic materials alter electromagnetic waves is supported by temperature increases. The ferromagnetic density of the orthodontic materials used was shown to be closely connected to temperature increase.

The glass of composition 60Bi 2 O 3 –10SrO–30Fe 2 O 3 (BSFO) (in mol%) was prepared by conventional melt quenching technique. Heat treatment process was applied to the glass samples at temperature close to crystallization temperature (600 °C) for different time intervals of 0, 2, 4 and 8, respectively, to obtain glass ceramic nano-composites. X-ray diffraction (XRD) patterns displayed the formation of a cubic Bi 3.43 Fe 0.57 O 6 for BSFO glass-ceramic nano-composites. The average nanocrystallite size (D) was determined to be between 13.48 and 17.26 nm. The values of D of the present samples were increased with an increment of heat treatment time. The high resolution-transmission electron microscope (HRTEM) images of a BSFO glass sample that was heat treated at 600 °C for 4 h show the nanocrystallites dispersed in the glass matrix with particle size in the range of 17 nm. The real part of permittivity (ε′) of BSFO decreased sharply with the increment in frequency for all samples. The decrement in the magnitude of the real part of impedance (Z′) with the increment in both frequency and temperature suggests an increase in ac conductivity σ ac. The correlated barrier hopping (CBH) model can explain the exponent S and temperature behavior we observed throughout all samples. For all glass–ceramic nano-composites, with an increase in the electric field, remnant polarization P r increases. This confirms its ferroelectric nature. The energy storage density (W r) is found to be maximum for the HT 8 h sample and equal to 34.3 mJ/cm3. The efficiency (η) of the HT 8 h sample was 65 %. The (M − H) loops of the glass–ceramic nano-composites displayed an antiferromagnetic trend. These observations suggest that the present samples might be a promising option for producing energy storage devices. [ABSTRACT FROM AUTHOR]

The magnetic characters of VPd2Br4 spinel were calculated using different spin orientations, and electronic properties were investigated using different potential approaches. The ferromagnetic (FM) phase was the most stable magnetic state according to magnetic orientation calculations. The lattice parameter of VPd2Br4 spinel in the FM phase was obtained as 11.17 Å. Elastic analyses showed that the FM phase was mechanically stable. Cauchy's pressure (C12–C44), B/G ratio, and Poisson's ratio (ν) values were obtained as 22.819 GPa, 5.89, and 0.419 at 0 GPa pressure, respectively. Therefore, VPd2Br4 spinel was ductile at 0 GPa pressure. As a result of elastic calculations, Debye temperature was obtained as 136 K. The total magnetic moment value of VPd2Br4 spinel in the FM phase was obtained as 2.00 µB/f.u. The V-atom with a magnetic moment value of 1.868 µB was the most partial contribution to the total magnetic moment. According to electronic properties, minority electron states of VPd2Br4 spinel had semiconductor character, while majority electron states showed metallic character. The band gaps in the minority electron states were calculated as 1.358 eV, 1.705 eV, 2.011 eV, and 2.253 eV according to the GGA, GGA + 1 eV, GGA + 2 eV, and GGA + 3 eV approaches, respectively. These band gaps in the minority electron states and the metallic characters in the majority electron states indicated that VPd2Br4 spinel had 100% spin polarization. Thus, using different approaches, VPd2Br4 spinel was obtained as a true half-metallic material in the FM phase. [ABSTRACT FROM AUTHOR]

Here in the present work, simple, eco-friendly and economical method of synthesis has been approached known as hydrothermal synthesis that allowed easy doping of Fe ions into the ZnS host lattice. A unique approach was adopted for the first time to prepare ZnS material where thioglycolic acid (TGA) was used as a source for sulfur in addition to a reducing and capping agent. Properties of the nanostructures were explored using different techniques. The X-ray diffraction (XRD) results indicated formation of single phase hexagonal ZnS material where inclusion of Fe2+ ions into the ZnS lattice have no influence on the crystal phase of the material. Probably almost identical sizes of Zn2+ and Fe2+ ions made this possible that indicated Fe2+ ions take Zn2+ vacant sites by substitution of Zn2+ ions by Fe2+ ions. Chemical analysis (X-ray photoelectron spectroscopy) performed discovered that Zn and Fe ions were present in +2 oxidation states whereas S is in −2 state. Anisotropic growth of the nanostructures is reported where irregular shaped nanostructures of varying dimensions were formed that agglomerated as doping concentration was increased to form spherical microstructures. Inclusion of Fe ions into the host material modified magnetic behavior of the nanostructures converting diamagnetic ZnS into a ferromagnetic material. Optical properties were also influence by the doping resulting in photon absorption at different wavelengths. The band gap got reduced from 3.2 eV to 2.7 eV making the ZnS nanostructures visible light active. The nanostructures with band gap 2.7 eV exhibited good photocatalytic activity against methylene blue (MB) dye under visible light illumination degrading 94% of the dye in just 2 h. The scavenging experiments performed showed hydroxyl free radicals play an active role in mineralizing the dye. Reusability and post photocatalytic properties of the photocatalysts determined their stability and potential ability for possible commercialization. [ABSTRACT FROM AUTHOR]

Perovskite oxides have attracted significant attention in energy storage performances, because of its eccentric physical and chemical features. Herein, we aim to study the electrochemical characterization of double perovskite La 2 NiMnO 6 (LNM) prepared through a facile sol-gel route. XRD profile portraited the formation of monoclinic structure with a space group P2 1 /n. The X-ray photoelectron spectroscopy highlighted the presence of La, Ni, Mn and O ions in La 2 NiMnO 6. SEM images validated the presence of uniformly distributed particles. The MnO 6 and NiO 6 octahedra's stretching "breathing" vibrations are assigned to the A g mode, whereas the combined modes of antistretching or/and bending motions are represented by the B g mode. Subsequent electrochemical performance evaluations of LNM electrode were conducted using cyclic voltammetry, galvanic charge-discharge studies, electroscopic Impedance spectroscopy and Ragone plot to interpret the nature of prepared sample. For a scan rate 10 mV/s, LNM shows specific capacitance of 9.16 mF/g and at current density of 0.1 A/g, it showed specific capacitance of 20.13 mF/g. The DC magnetic measurement shows the persistence of a dominating ferromagnetic long-range ordering below the Curie temperature (T C ∼286 K). Hence the result provides an opportunity to develop LNM for supercapacitor applications. [ABSTRACT FROM AUTHOR]

The article presents the results of a systematic study of the crystalline structure, microstructure, and hysteresis properties of (Cr80Mn20)/Fe bilayers, deposited on buffer coatings of various metals (Cr, Fe, W, Ta). It has been established that depending on the composition of the buffer coating and the thickness of the Cr–Mn layer, the latter develops body-centered cubic structure with either the (110) or (200) texture, or none. It is shown that the Cr–Mn layer is a source of increased coercivity in the adjacent Fe layer and when is in a certain structural state and has a relatively large thickness (100 nm) induces exchange bias in the Fe layer. The regularities obtained are interpreted in terms of the antiferromagnetic ordering of Cr–Mn and its relatively weak magnetic anisotropy. [ABSTRACT FROM AUTHOR]

Ultrafine nickel nanoparticles have been synthesized using a capping agent-assisted chemical reduction technique using two different reaction media - water and ethylene glycol. The effect of the capping agent and reaction medium concentration on the particle size and their magnetic properties have been extensively studied. The size of the nickel nanoparticles, as revealed from X-ray diffractograms and transmission electron micrographs, is less than 5 nm. The energy-dispersive X-ray spectrum confirms that the synthesized nanoparticles are pure nickel. No other element is present in the spectrum. The nanoparticles exhibit surface plasmon resonance in ultraviolet (-310 nm). The blue shift in the absorbance peak's position further confirms the particle's miniaturization. The samples should have exhibited superparamagnetic behavior because the particle size is in the nanometer range. Instead, the ferromagnetic behavior of the samples has been observed at ambient temperature, which is attributed to the formation of clusters of nanoparticles. This property makes the material applicable for data storage technology. [ABSTRACT FROM AUTHOR]

Nanocomposites of (Mg0.9Ni0.1O)x/(CoFe2O4)1-x, with 0 ≤ x ≤ 1 in weight fractions, were synthesized through the co-precipitation method followed by high-speed ball milling. The investigation of the structural, optical, and magnetic properties was conducted for the synthesized samples. X-ray diffraction (XRD) analysis confirmed the formation of CoFe2O4 and Mg0.9Ni0.1O distinct phases in the nanocomposites without any detectable impurities or minor phases. Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) revealed the presence of spherical particles in both the individual phases and their nanocomposites. Raman spectroscopy exhibited strong, well-defined modes for CoFe2O4, indicating its spinel phase formation, while Mg0.9Ni0.1O displayed two broad peaks (G and D bands). X-ray photoelectron spectroscopy (XPS) was utilized to analyze the elemental compositions and oxidation states (Co2+, Fe2+, Fe3+, Mg2+, Ni2+, and O2−). The magnetic measurements revealed the soft ferromagnetic behavior of pure cobalt ferrite and a combination of weak ferromagnetism and paramagnetic behavior at high magnetic fields for pure Mg0.9Ni0.1O. [ABSTRACT FROM AUTHOR]

This study investigates the structural and magnetic properties of pyrochlore Lu 2 V 2 O 7 material. The ferromagnetic transition in pyrochlore Lu 2 V 2 O 7 has been confirmed at a Curie temperature (Tc = 73 K). In addition, the Raman spectrum is measured to introduce structural material observation. Raman investigations demonstrate that many vibrational motions are observed in the pyrochlore system. The Raman spectra were taken between 78 and 295 K and a frequency range of 100–1200 cm−1. In Raman measurement, the Lu 2 V 2 O 7 sample exhibits four different vibrations. All vibrational modes show temperature dependence. At room temperature, the first two peaks (A and B) appeared at lower spectrum (152.7 cm−1 and 227.5 cm−1), respectively, and the last two peaks (C and D) are observed at higher spectrum (307.1 cm−1 and 524.9 cm−1) ( 307.1 cm - 1 and 524.9 cm - 1 ). The magnetization measurement confirmed that the ferromagnetic transition occurred at a Curie temperature of Tc = 73 K. [ABSTRACT FROM AUTHOR]

New (Er1 –xYx)0.8Sm0.2Fe2 multicomponent alloys with a substitution parameter of x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0 are synthesized and their atomic crystal structure and magnetic properties are studied. It is shown that full magnetic compensation can be expected in the region of 0.2 < xcomp < 0.4. Er0.8Sm0.2Fe2 alloy exhibits temperature-dependent magnetization compensation at Tcomp = 400 K. [ABSTRACT FROM AUTHOR]

In the current paper, hematite (α Fe2O3) nanoparticles (NPs) were prepared by the chemical co-precipitation method. These synthesized nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Raman spectroscopy, and vibrating sample magnetometry (VSM). The XRD studies for the nanoparticles revealed rhombohedral symmetry with space group: R3c (167), and the particle size is about 33.34 nm. The morphological studies carried out by SEM indicated that these prepared samples have a spherical morphology with some porosity. The specific surface area of this sample was calculated by the Brunauer–Emmett–Teller (BET) technique. FTIR spectroscopy confirms the Fe–O and O–Fe–O vibrations corresponding to stretching at the expected positions (520 cm−1) related to the structure. From Raman data, modes corresponding to α-Fe2O3 are seen. From DC magnetisation studies, the current sample shows ferrimagnetic behavior. In addition, the value of Ms is 1.027 and value of Mr is 322.787×10–6. Further nanofluids of these nanoparticles with different concentrations of transformer oil were prepared. The performance of this nanofluid as a coolant in transformer oil was also studied. The 0.2 g/l concentration shows the maximum improvement in breakdown voltage. Hence, under optimal conditions, these ferrofluids can perform well for insulating purposes. [ABSTRACT FROM AUTHOR]

Objective: Public exposure to radiofrequency (RF) fields from fifth generation (5G) and other sources is known to be below human exposure limits. The interaction of RF fields with the human body has been widely documented, with tissue heating being the primary consequence for RF fields above 100 kHz. This study aimed to reveal possible harm to orthodontic patients associated with 5G electromagnetic waves. The possibility of individuals with orthodontic appliances (metallic braces, porcelain braces, thermoplastic appliances) being more affected by 5G was investigated. Methods: Sixty extracted human teeth were divided into 5 groups. Different types of brackets, arch, and ligature wires were applied to each group. Each group was exposed to 5G electromagnetic waves (3.6 GHz of frequency) for 60 minutes. Temperature measurements were made inside the canine root canals and in saline solution. Results: Exposure to a 5G electromagnetic field increased the temperatures of the root canal of the tooth and sodium chloride (NaCl) solution surrounding samples. Temperature increase in the canals were as follows; metal self-ligating braces > mini metal braces > porcelain braces > clear aligner > control. The temperature change in the NaCl solution at the 60th minute was close to each other in the self-ligating braces and mini metal braces groups. The temperature rise of the NaCl solution in the control group was also minimal. Conclusion: The hypothesis that orthodontic materials alter electromagnetic waves is supported by temperature increases. The ferromagnetic density of the orthodontic materials used was shown to be closely connected to temperature increase. [ABSTRACT FROM AUTHOR]

Electromagnetic absorbing composites modified by ceramic- ferromagnetic-graphite (CFG) fillers were first received. Ceramic-ferromagnetic-graphite polymer composites impact strength characteristics were researched and compositions with a higher silicon carbide SiC-10 % wt. content were studied, while chromium oxide Cr2O3 and graphite content in 5-15% wt. range was optimized. It is shown, that chromium oxide Cr2O3 and graphite introduction in polyamide 6-SiC 10 % wt. system increases their impact strength and breaking stress during bending. As a result of statistical data processing, the approximating curves equation were obtained, which allow to calculate ceramic-ferromagnetic-graphite polymer composites strength characteristics. It is shown that the nature of modification effect for CFG fillers on ceramic- ferromagnetic-graphite polymer composites complex spectral characteristics for absorbing electromagnetic radiation indicates the advantage in using complex system in order to receive effective materials. [ABSTRACT FROM AUTHOR]

A series of high entropy manganite perovskites (La 0. 2 Pr 0. 2 Nd 0. 2 Bi 0·2 Ba 0. 2)MnO 3 , (La 1/6 Pr 1/6 Gd 1/6 Bi 1/6 Sr 1/6 Ba 1/6)MnO 3 , (La 0.2 Nd 0.2 Gd 0.2 Sr 0·2 Ba 0.2)MnO 3 and (La 1/6 Pr 1/6 Nd 1/6 Ca 1/6 Sr 1/6 Ba 1/6)MnO 3 with variable hole concentration at fixed A-site ionic radius ( = 1.253 Å) have prepared by sol-gel technique. Single phase samples were characterized by the powder X-ray diffraction (PXRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray (EDX) analysis and elemental mapping which confirm the phase purity of the samples, surface morphology, elemental ratio and chemical homogeneity. X-ray photoelectron spectroscopic (XPS) studies reveal the increase of Mn4+ ions systematically with the substitution of hole concentration at A-site. Magnetization study in this high entropy sample with variable hole concentration at fixed = 1.253 Å exhibits several contrasting behaviour compare to the conventional hole doped samples. In these high entropy manganites the variation in critical temperature (T C) does not follow expected trend neither with the hole concentration nor to the cationic size disorder parameter, σ 2. Though the is fixed, there is a slight increase in tolerance factor (f) due to hole variation in B-site. Interestingly, T C variation with f shows similar trend to the hole concentration, which is expected to be increased linearly. The effect of f on T C is rather weaker in comparison to σ 2. The large drop in T C for high entropy system with respect to the conventional manganite is related to the local structural distortion which severely hampers the Mn3+—O—Mn4+ double exchange interaction. The competing magnetic interactions lead to magnetic phase separation as well as Griffith like phase. Spin pinning is noticed for the samples containing six elements in A-site which is independent on hole concentration. Possible spin clustering is also realized above ferromagnetic T C. Careful analysis of the magnetization data suggests that observed anomaly in magnetic behaviour can be ascribed to the local chemical disordering apart from the size disorder parameter. The possible role on magnetic properties of the number of elements occupying in a crystallographic site is emphasized. [ABSTRACT FROM AUTHOR]

This study successfully synthesizes magnetic fluorescent iron oxide silica core/shell nanocomposites (MFSNC) derived from natural geothermal silica. The nanostructures comprise an iron-oxide core and a fluorescent mesoporous silica outer layer. X-ray diffraction (XRD) analysis indicated diffraction peaks of amorphous silica with crystallites of magnetite types in the MFSNC samples. Transmission electron microscopy combined with energy-disperse X-ray spectroscopy were used to observe the morphological structure, which showed nanoparticles of MFSNC with Fe, Si, O, and N elements. Among varying ratios of ferric salts, the MFSNP0.5 sample exhibited the highest fluorescence intensity (280.5073 a.u.). It demonstrated superior fluorescence stability in water (pH = 7) compared to other samples, as investigated by fluorescence spectrophotometer. Additionally, this sample displayed ferromagnetic properties, with a magnetic saturation (MS) of 14.57 emu/g and a loop area value of 0.7 kOe.emu/g, determined by the vibrating sample magnetometry. This work details the successful synthesis of MFSNC nanocomposites with tailored magnetic and fluorescent properties. Notably, the MFSNC0.5 sample stands out for its superior fluorescence intensity, stability in water, and desirable ferromagnetic characteristics. Highlights: Synthesizes magnetic fluorescent iron oxide silica core/shell nanocomposites (MFSNC) derived from natural geothermal silica. MFSNC0.5 sample stands out for its superior fluorescence intensity, stability in water, and desirable ferromagnetic characteristics. MFSNC displayed ferromagnetic properties, with a magnetic saturation (MS) of 14.57 emu/g and a loop area value of 0.7 kOe.emu/g. [ABSTRACT FROM AUTHOR]

Results of XRD and TEM studies of a metastable phase state in Fe73Ti5B19O3 and Fe55Ti16B27O2 films, which is formed upon magnetron deposition under preset conditions, and of the evolution of the state in the course of subsequent annealing at 500 °C for 1, 5, and 9 h and experimental data on the magnetic microstructure and magnetic properties are reported. The annealed films were found to be characterized by a nanocrystalline structure, which is represented by two crystalline phases, namely, the ferromagnetic solid solution αFe(Ti), and nonferromagnetic boride FenB. The Ti content in the films determines the grain size of the αFe(Ti) phase, whereas the content of B localized within the grain boundaries determines the ratio of the volume fractions of amorphous and nanocrystalline phases in the structure. In contrast to the ferromagnetic Fe73Ti5B19O3 films, the Fe55Ti16B27O2 films are superparamagnets both in the deposited state and after annealing at 500 °C for 1 and 5 h because of the higher volume fraction of the amorphous phase in the structure. The 9 h annealing of the Fe55Ti16B27O2 films transfers them into the ferromagnets owing to the development of the amorphous phase crystallization, increase in the content of nanocrystalline ferromagnetic phase αFe(Ti) grains, and realization of exchange interaction between them. [ABSTRACT FROM AUTHOR]

Herein, a first-principles study on the structural, electronic, optical and magnetic properties of SrCo 1 − x AxO3 (A = Fe or Cr, x = 0. 1 2 5 and 0.25) was conducted. For all calculations, ultrasoft pseudo-potentials plane wave (USPPW) and the generalized gradient approximation (GGA) with the default exchange-correlation parameterization of Perdew–Burke–Ernzerhof (PBE) were employed and with Hubbard correction. The crystal structures of SrCo 0. 8 7 5 A 0. 1 2 5 O3 and SrCo 0. 7 5 A 0. 2 5 O3 (A = Fe or Cr) are determined as a supercell of 2 × 2 × 2 cell cubic perovskite structure (Pm-3m) with symmetry space group No. 221. No energy gap was observed at the Fermi level for both SrCo 0. 8 7 5 Cr 0. 1 2 5 O3 and SrCo 0. 7 5 Cr 0. 2 5 O3 compounds, indicating their metallic properties. The magnetic moment calculations showed that the doping of Fe into SrCoO3 resulted in a higher net magnetic moment and all materials studied here was ferromagnetic ground states. Dielectric functions indicate the metallic conductivity for all materials studied here. The different values of the real part for materials present that this material has a Drude-like dielectric function behavior. [ABSTRACT FROM AUTHOR]

The wide band gap of complex oxides is one of the critical challenges restricting their usage in photovoltaic cells. Therefore, examinations of their photoelectric characteristics have increasingly concentrated on materials with a low band gap. This work investigated the effects of iron doping on samarium-modified Bi4Ti3O12-based oxides (BSmT) made via a solid reaction approach to control the band gap of complex oxides. X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), and X-ray photoelectron spectroscopy (XPS) were used to study the synthesized materials' structural, optical, and oxygen vacancies. Doping with Fe atoms significantly increased the tunability of the band gap from 3.20 eV to 1.81 eV without violating symmetry. The tuning of bandgap energy in this system was explained based on structural distortion and the formation of oxygen vacancies. This work examined the ferromagnetism and ferroelectricity ordering of the sintered BSmT:F0% and BSmT:F10% samples at room temperature to demonstrate the multiferroelectricity behavior. The findings indicate unsaturated P-E hysteresis loops driven by domain pinning caused by oxygen vacancy formation near domain boundaries. Simultaneously, significant S-type M-H hysteresis loops showed weak ferromagnetic ordering. The findings in this study are encouraging for the development of intrinsic multiferroics for photovoltaic devices for future applications. [ABSTRACT FROM AUTHOR]