Search

This study aimed to enhance the surface defects and fluorescence properties of GdPO₄·H₂O:Tb³⁺ nanophosphors and develop a nanoscale dual-layer core-shell structured fluorescent probe, GdPO₄·H₂O:20%Tb³⁺@GdPO₄@PEG. Hydrothermal and microwave synthesis methods were employed. The former controlled the ratio of GdPO₄·H₂O:Tb³⁺ to GdPO₄, forming core-shell structured nanophosphors GdPO₄·H₂O:20%Tb³⁺@GdPO₄ with varying shell thicknesses. The latter involved Polyethylene Glycol (PEG) as a surface modification agent, resulting in a high-performance dual-layer fluorescent nanomaterial, GdPO₄·H₂O:20%Tb³⁺@GdPO₄@PEG. We characterized the modified and unmodified fluorescent powders for their structural, morphological, optical, and magnetic properties using XRD, SEM, TEM, FTIR, TG, FL, and VSM techniques. Both pre- and post-coated nanophosphors exhibited a singular hexagonal crystal structure with an ellipsoidal morphology, average particle sizes of approximately 40–50 nm, and coating layer thicknesses of about 5–15 nm. The excitation and emission peak positions remained relatively constant before and after the coating process. The dual-layer core-shell nano-fluorescent probe demonstrated significantly enhanced fluorescence intensity due to reduced non-radiative transition rates. Moreover, both pre- and post-coated nanophosphors exhibited excellent paramagnetic properties. This research successfully improved the hydrophilicity and biocompatibility of GdPO₄·H₂O:Tb³⁺ nanophosphors while concurrently enhancing their luminescent and magnetic performance. [ABSTRACT FROM AUTHOR]

The structural, microstructural, dielectric, optical, ferroelectric, and magnetic properties of cobalt doped barium calcium titanate (BCT) (Ba 0.80 Ca 0.20 Ti 1-x Co x O 3 with x = 0.000, 0.005, 0.010, 0.015, and 0.020) ceramics have been reported in this paper. The ceramic samples were prepared by the conventional solid-state reaction method. For all of the prepared samples, the tetragonal structure with the space group P 4 mm has been confirmed using the refinement method through Rietveld refinement of X-ray diffraction patterns. Field Emission Scanning Electron Microscopy (FESEM) micrographs revealed that the average particle size exists in micrometre range (0.3–0.8) μm. Optical studies revealed a gradual decrease in the energy bandgap from 3.31 eV to 2.71 eV with increasing doping concentration. A decreasing trend was observed in the dielectric characteristics of the material with changing frequencies at room temperature. Ferroelectric (P-E loops) analysis displayed an increase in both remnant polarization and maximum polarization of the ceramic with the increasing applied electric field. The highest value for the energy storage efficiency (η) was calculated to be 20.51 %. Magnetic analysis conducted at room temperature revealed the enhancement in ferromagnetism with the increase in doping concentration. [ABSTRACT FROM AUTHOR]

To meet the needs for higher energy efficiency and a wide operating temperature range of electric vehicles, the low‐loss MnZn ferrites in a wide temperature range have been developed by optimizing the Fe content and the oxygen partial pressure (PO2) during the sintering process in this work. For the optimal sample, power loss at 300 kHz/100mT is 204 kW/m3 at 25°C and remains below 290 kW/m3 in the wide temperature range from ‐10 to 120°C. The loss separation method was employed to clarify the effects of the Fe content and PO2 on power loss. The equivalent circuit model has been employed to fit the complex impedance and it is found that the increase of PO2 enhances both the grain resistance Rg and the grain boundary resistance Rgb. The enhancement of Rgb is mainly responsible for the reduction of eddy current loss and consequently power loss. Dielectric permittivity is as large as about 15000 in this series of samples due to the electric polarization at the rich grain boundaries. Dielectric loss is very low between ‐50 and 150°C and has little contribution to the energy loss. [ABSTRACT FROM AUTHOR]

In this study, the sol-gel synthesis technique was harnessed to craft nanocomposites of (1-x)La 0.7 Sr 0.3 MnO 3 -(x)BTO with x values of 0.4, 0.6, and 0.8. The attributes of these meticulously engineered materials were exhaustively explored using a diverse suite of characterization methods. X-ray diffraction analysis irrefutably confirmed the phase purity of the perovskite structure, emphasizing the synthesis's precision. Furthermore, Diffuse Reflectance Spectroscopy shed light on the optical properties of the nanocomposites, revealing a significant shift in bandgap energy that correlated directly with the BTO concentration. Specifically, an increment in BTO concentration resulted in a systematic expansion of the bandgap from 1.51 eV to 1.44 eV. For an in-depth analysis of the magnetic characteristics of the composites, Vibrating Sample Magnetometry was utilized. The magnetic analysis identified a conspicuous reduction in saturation magnetization, highlighting the complex interplay between the composite components at the nanoscale. Additionally, the dielectric properties were rigorously investigated through dielectric measurements, which unveiled a notable increase in the dielectric constant, accompanied by the emergence of novel relaxation behaviors. This finding indicates that adjusting the BTO content within the nanocomposites not only modifies their dielectric properties but also provides a method for fine-tuning their functional performance. [ABSTRACT FROM AUTHOR]

The susceptibility of either oxidation into Sn(IV) or disproportionation into Sn(IV) and Sn(0) limits the study of metal tin‐(II)‐borate ceramics. We report mullite‐type SnCrBO4 and SnVBO4 synthesized in sealed quartz tubes by conventional solid‐state method. X‐ray powder diffraction data Rietveld refinements confirm that both compounds are isostructural to PbMBO4 phases for M = Al, Ga, Cr, Mn, and Fe. The end‐members show a complete miscibility within the Sn(Cr1−xVx)BO4 solid solution. Both the microstructural (average crystallite size, microstrain, and degree of crystallinity) and crystal structural (metric parameters, bond lengths, polyhedral volume, and polyhedral distortion) parameters are observed with respect to the compositional x‐value. The stereochemical activity of the 5 s2 lone electron pairs of Sn2+ cations has been measured by using the Wang–Liebau eccentricity parameter. The structural features are complemented by 119Sn Mössbauer, Raman, and Fourier‐transformed infrared spectroscopy. The 119Sn Mössbauer isomer shifts and the quadrupole splitting values confirm the SnO4 coordination and an Sn(II) valence state. The electronic band gap has been calculated from the UV/Vis diffuse reflectance spectra, which slightly increases with successive decrease of the cationic radius from V to Cr. Temperature‐dependent inverse DC magnetic susceptibility suggests that SnCrBO4 and SnVBO4 are antiferromagnetic and ferromagnetic (FM) with a Néel temperature of 17.2(1) K and a Curie temperature of 29.8(1) K, respectively. Alike the end‐member SnVBO4, Sn(Cr0.5V0.5)BO4 is also found to be a rare FM insulator. The thermal stability decreases with increasing vanadium content in the solid solution. [ABSTRACT FROM AUTHOR]

M-type hexagonal ferrites have received widespread attention for their excellent magnetic properties, but studying the intricate interplay between their composition, process and magnetic properties has long been a puzzling task. The advent of machine learning offers a promising example for accelerating the discovery of connections between them. In this work, we trained five machine learning regression models (SVR, DTR, AdaBoost, GBDT and MLP) using data collected from the literature and found that the SVR model performed well on the dataset. In order to verify the feasibility of the SVR model, we predicted the magnetic properties of Ba 1-x La x Fe 12-y Mn y O 19 (0.1≤x=y≤0.6), and then prepared and tested them. The results showed a good agreement between the prediction and the experiment, which proved the reliability of the designed model. Moreover, we elucidate the occupancy trend of Mn3+ ions by first principles calculation and Raman spectroscopy verification. This work strongly suggests that machine learning has the potential to explore the relationship between composition, process and properties, which opens the door for the tailoring the properties of M-type hexagonal ferrites. [ABSTRACT FROM AUTHOR]

Cu80Co20/CNT nano-composites were prepared by mechanical alloying for various duration of time. The effects of CNT addition on Co solid solubility in Cu morphology, magnetic and electrical characteristics of the samples were analyzed using state-of-the-art methods, such as x-ray diffraction (XRD), differential thermal analyzer (DTA), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), superconducting quantum interference device (SQUID) and four point probe technique, respectively. In a sample that was milled for 10 h, it was demonstrated that the solid solubility of Co in Cu increased to 20 wt.%; however, CNTs in Cu80Co20/CNT nano-composites prevented this from happening. 10 h after mechanical alloying, CNTs were uniformly dispersed throughout the metal matrix, and the resulting products were agglomerates of nanoparticles. The addition of CNTs changed the magnetic properties of nano-composite samples, according to analysis of magnetic hysteresis loops. The saturation magnetization and coercivity of composite samples increased with increasing CNT content because of the non-dissolved paramagnetic Co in nano-composites and the exchange coupling phenomenon. Cu-Co/CNT nano-composites' electrical resistance increased with CNT concentration. [ABSTRACT FROM AUTHOR]

Electrospinning technology is widely used for preparing biological tissue engineering scaffolds because of its advantages of simple preparation, accurate process parameters, and easy control. Poly(L-lactide) (PLLA) is regarded as a promising biomass-based polymer for use in electrospinning. The incorporation of Fe3O4 nanoparticles (NPs) could improve the osteogenic differentiation and proliferation of cells in the presence or absence of a static magnetic field (SMF). In this work, these two materials were blended together to obtain electrospun samples with better dispersibility and improved magnetic properties. First, composite PLLA and Fe3O4 NP fibers were prepared by means of electrospinning. The influence of electrospinning conditions on the morphology of the composite fibers was then discussed. Changes in magnetic properties and thermal stability resulting from the use of different PLLA/Fe3O4 mass ratios were also considered. Next, the morphology, crystal state, thermodynamic properties, and magnetic properties of the electrospun samples were determined using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and vibration sample magnetization (VSM). The results showed that the fibers prepared using PLLA with Mn = 170,000 exhibited good morphology when electrospun at 12 KV. The magnetic properties of PLLA/Fe3O4 composite electrospun fibers increased with the NP content, with the exception of thermal stability. The results of the present study may help to promote the further development of PLLA/Fe3O4 composite materials in the biomedical field. [ABSTRACT FROM AUTHOR]

In this study, we successfully fabricated Fe61Zr10Co5Mo7W2B15 and Ni61Nb19.2Ta19.8 amorphous fibers (AFs) using the melt-extraction method. This method ensured a rapid cooling, uniform quality, minimal defects, and superior performance. Magnetic property analysis revealed that the Fe-based AFs exhibited a single-slope magnetization curve characteristic of paramagnetic or diamagnetic materials, while the Ni-based AFs displayed a rectangular curve with low magnetic hysteresis, typical of ferromagnetic materials. The axial saturation magnetization of as-prepared Ni-based AFs is ~1.5 × 10−7 emu/g, with a coercivity of about 85 Oe. The statistical analysis of tensile tests indicated that Ni-based AFs possess a higher fracture threshold of 2440 ± 199 MPa and a reliability of 14.7, demonstrating greater material safety and suitability for high-performance applications. As opposed to Ni-based AFs, Fe-based AFs present a fracture threshold and of 1582 ± 692 MPa and a reliability 4.2. Moreover, under cyclic loading conditions, Ni-based AFs exhibited less residual deformation and superior elastic recovery with a fracture strength of 2800 MPa. These findings highlight the potential of Ni-based AFs for advanced engineering applications, particularly where high strength, durability, and excellent magnetic properties are required, paving the way for their integration into next-generation technologies. [ABSTRACT FROM AUTHOR]

Carboxylato-bridged dinuclear and tetranuclear Mn(II) complexes 1–3 with ditopic ligands featuring two N3-terminal coordination sites connected by hexyl (tphn), octyl (tpon), and p-xylyl (tpxn) linkers have been synthesized and characterized through X-ray single-crystal structure analyses, infrared spectroscopy, and elemental analyses. Complex 1 is a μ-fluorido-bis-μ-acetato dinuclear Mn(II) complex where the ligand tphn coordinates to both terminal sides of a dinuclear Mn unit. In contrast, complexes 2 and 3 are tetranuclear Mn(II) complexes with a macrocyclic structure, in which two dinuclear Mn units are linked by ligands tpon or tpxn. The redox behaviors of 1 and 2 were elucidated by cyclic voltammetry, revealing two metal-centered redox processes corresponding to Mn2(II,II)/Mn2(II,III) and Mn2(II,III)/Mn2(III,III). [ABSTRACT FROM AUTHOR]

Using first-principles calculations based on density-functional theory, this paper investigates the electronic structure and magnetic properties of the Heusler alloy Mn2LiGe bulk and its (001) surfaces. The Mn2LiGe bulk is demonstrated to be inverse Heusler alloy with space group of F43m and lattice constant of 5. 87 Å. A direct band gap with a width of 1. 1 eV near the Fermi surface of the spin-down channel is detected. The Mn2LiGe bulk possesses stable half-metallic and magnetism in the lattice constant range of 5. 55 - 6. 33 Å. In addition, six different surface structures of Mn2LiGe are constructed in this paper. The first layer atoms on the surface undergo different displacements, increasing the surface roughness. Due to surface effects, the magnetic properties of atoms on the surface are different compared to those in the bulk. Both the MnA MnA and MnB MnB surface structures have the highest magnetic moments, while the LiLi and the GeGe surface structures have the lowest magnetic moments. Electronic structure calculations show that the half-metallic band gap present in the bulk is destroyed in all six surface structures and the spin polarization is weakened in varying degrees. Only the LiLi surface structure maintains up to 99. 9% of the surface spin polarization, making the surface an excellent prospect for applications in spintronic devices. [ABSTRACT FROM AUTHOR]

The utilization of magnetoelectric composites, particularly core-shell configurations, enhances their versatile applications in various sectors such as medicine and data storage. Among these composites, the perovskite-spinel combination is distinguished by its significant potential. A series of (1-x) BiFeO 3 -(x) CoFe 2 O 4 (where x = 0.0, 0.2, 0.5, and 1.0) nano core-shell structures were synthesized using a sol-gel auto-combustion method to explore their multifunctional capabilities. Structural analyses identified peaks corresponding to both perovskite and spinel phases. Field Emission Scanning Electron Microscopy revealed a reduction in average particle size with an increase in CoFe 2 O 4 content.The particle size in the BFO80-CFO20 sample has been reduced from 243 nm to 34 nm. Additionally, Transmission Electron Microscopy images of the BFO80-CFO20 sample highlighted the evolution of core-shell structures. Our findings indicate that higher CFO concentrations significantly affect the dielectric, ferroelectric, and optical properties. The bandgaps of the nanocomposites BFO80-CFO20 and BFO50-CFO50 were estimated to be 1.43 eV and 1.39 eV, respectively. Magnetic analysis showed increases in both saturation magnetization and remanent magnetization with increased CFO content, while the coercive field followed a different trend. The saturation magnetization values for the samples BFO, BFO80-CFO20, BFO50-CFO50, and CFO were calculated as 0.205, 14.612, 28.374, and 74.105 (e m u g r) , respectively. The measured values for the same samples were 0.08, 5.07, 11.34, and 34.01 (e m u g r) , respectively. Further, the electrochemical properties were thoroughly investigated using cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

An effective method to improve the magnetic properties of soft-magnetic composites (SMCs) is insulation coating, which is achieved by inducing an interfacial solid-phase reaction via hot-pressing sintering. Herein, an interfacial solid-phase reaction was induced at the SMC interface through salt compound decomposition and the doping of carbonyl iron powder (CIP). Furthermore, FeSiAl-based SMCs with various CIP amounts were prepared. Results show that during hot-pressing sintering, calcium acetate coated on the FeSiAl matrix decomposes. Furthermore, the generated reactive oxygen species cause Si and Al migrations to the heterogeneous interface; in combination with the decomposition product CaO, these migrations result in the in situ formation of a CaSiO 3 ·SiO 2 ·Al 2 O 3 composite insulation layer on the matrix surface. CIP added to the hydrothermal insulation coating exhibits good plasticity, and its combination with the coating layer improves the compressibility of composite powders and eliminates pores within SMCs. In hot-pressing sintering, CIP addition hinders the conversion of Si to SiO 2 , resulting in excess reactive oxygen species that react with Al in the FeSiAl matrix to yield a higher Al 2 O 3 content. With an increase in the CIP amount, more Si diffuses into CIP such that the magnetic phase inside FeSiAl-based SMCs changes from a single Al 0.3 Fe 3 Si 0.7 phase to a mixed phase comprising an Al 0.3−x Fe 3 Si 0.7−y phase, CIP and CIP–Si. However, excessive CIP addition can cause the re-formation of pores inside SMCs and deterioration of magnetic properties. By changing CIP addition amounts, the magnetic properties of SMCs are precisely regulated. When the CIP addition amount is 9 wt%, the prepared SMCs exhibit optimal magnetic properties, with the highest saturation magnetisation of 134.5 emu/g and permeability of 44.1 at 10 mT and 500 kHz, along with a core loss as low as 198.8 kW/m3 at 20 mT and 100 kHz. [Display omitted] [ABSTRACT FROM AUTHOR]

This study explores the remarkable properties of liquescent open‐shell ionic molecular systems, emphasizing the magnetic and photophysical characteristics arising from their associated structures in the condensed state under various conditions. Well‐investigated open‐shell molecules, namely, phenothiazine, dihydrophenazine, and tetrathiafulvalene radical cations, and bis(malononitriledithiolato)nickel(III) anionic complexes were examined, and the concept of liquescent open‐shell ionic molecular systems was devised. Transformations in their associated structures are induced by external stimuli, resulting in significant variations in their physical properties. These experimental findings open new avenues for exploring and applying stimuli‐responsive molecule‐based materials. [ABSTRACT FROM AUTHOR]

The structural, electronic, magnetic, and optical properties of Co-doped 10–20-atom silver clusters are investigated by GGA/PBE via the density functional theory. The Ag–Co clusters form core–shell structures with a Co atom in the center. Co atom doping modulates electronic properties like energy gap, molecular softness, global hardness, electronegativity, and electrophilicity index. For the optical spectra of the Ag–Co clusters, the energy of their spectra overall exhibits little change with increasing numbers of atoms; the strongest peaks are roughly distributed at 3.5 eV, and the intensity of their spectra overall is strengthened. Raman and vibrational spectra reflect structural changes with Co atom addition. The addition of the Co atom alters magnetic moments of specific Ag–Co clusters, while others remain unchanged. [ABSTRACT FROM AUTHOR]

The alloy 50Ag−50Mn (wt.%) was prepared using ball milling. After 50 h of milling, the samples were isothermally annealed for 1 h at a time at three different temperatures ranging from 350∘C to 550∘C. By analyzing the X-ray diffraction data, Rietveld refinement structure analysis was used to measure the lattice strain and crystallite size. The introduction of lattice strain and the decrease in crystallite size as a function of milling time may both contribute to the increase in coercivity. The analysis of superconducting quantum interference devices demonstrates the soft ferromagnetic behavior of as-milled and annealed Ag−Mn alloy. After being annealed at 350∘C for 1 h, the 50Ag−50Mn alloy's maximum coercivity was discovered to be 253 Oe. [ABSTRACT FROM AUTHOR]

A cobalt ferrite (CoFe2O4) nanoparticle is harvested through sol–gel method. The various percentage of PVP (2.5, 5.0, 7.5, 10.0 and 12.5%) was added to the initial solutions and is acted as a chelating agent. Through X-Ray diffraction examinations results confirmed the single phase CoFe2O4 and had bigger crystallite size. The functional analysis is found through Fourier transform infrared spectroscopy (FTIR) studies. The optical analysis carried out through UV–visible spectrometer and a direct bandgap were determined. The surface features and its content of elements in the samples were found through scanning electron microscope (SEM) with energy dispersive (EDAX) analysis. The detailed magnetic characteristics of the resulting sample were found through vibrating sample magnetometer (VSM). Through TG/DTA measurements the decompositions and anionic oxidation—reduction were analysed. The dielectric constant and related parameters with respect to applied frequency are discussed through LCR measurement. The electrochemical behavior of the samples was tested through cyclic voltameter setup. And finally concluded with the merits and demerits. [ABSTRACT FROM AUTHOR]

The synthesis of SnO2 nanoparticles doped with varying concentrations of Fe was carried out using the sol–gel method. The resulting samples underwent analysis using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), ultraviolet–visible spectroscopy (UV–Vis), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy, and vibrating sample magnetometry. The purpose of this investigation was to examine the impact of doping on the structural, optical, and magnetic properties of the nanoparticles. The XRD study demonstrated a discernible alteration in the size of the crystalline structure as a function of the concentration of doping. The study revealed a noticeable variation in crystallite size, ranging from ~ 13 to 5 nm, as the Fe doping concentration increased from 0 to 7 mol%. This observation suggested that the rise in Fe content effectively hindered crystal development. The estimation of the optical band gap was performed using the Kubelka–Munk equation, revealing a decrease in the band gap for a specific doping concentration of Fe. The photoluminescence (PL) spectra obtained at room temperature indicated a red shift in the peak positions of the pristine SnO2 samples upon Fe doping. This observation provides confirmation of the reduction in the band gap of SnO2 resulting from the incorporation of Fe dopants. The nanoparticles doped with 5% Fe exhibited superior optical characteristics compared to the remaining samples. Furthermore, magnetic properties were determined by investigating magnetization vs. applied fields. Ferromagnetic interaction was observed in all the systems of SnO2 doped with Fe. To achieve a comprehensive understanding, the utilization of density functional theory was employed. The electronic states and density of states behavior were computed to accurately anticipate the arrangement of lattice sites and the corresponding presence of atoms. Theoretical computations were conducted using the VASP program. [ABSTRACT FROM AUTHOR]

Herein, Fe–Si–Al-based soft magnetic composites (SMCs) doped with carbonyl iron powders (CIPs) at different concentrations were successfully prepared. The reaction between CIPs and core–shell Fe–Si–Al/SiO 2 heterogeneous composite powders, induced by the high temperature and concentration gradient during heat treatment, was investigated. The effect of doping CIPs at different concentrations on the microstructure and magnetic properties of Fe–Si–Al-based SMCs was also studied. During heat treatment, the Fe–Si–Al/SiO 2 powders inside the SMCs exhibited a complex reaction with the doped CIP. The reaction involved multidirectional migration of Al and Si, evolution of an Al 2 O 3 + SiO 2 -composite insulating layer and formation of composite ferromagnetic phases. Furthermore, the density, saturation magnetisation, permeability and core loss of Fe–Si–Al-based SMCs were improved by doping the composites with moderate amounts of CIPs. The Fe–Si–Al-based SMCs doped with 8-wt% CIPs exhibited the best comprehensive magnetic properties (permeability = 43.5, saturation magnetisation = 160.1 emu/g and core loss = 481.7 kW/m3 at 10 mT and 100 kHz). Compared with undoped Fe–Si–Al-based SMCs, the permeability and saturation magnetisation increased by 40.3% and 24.0%, respectively, and the core loss decreased by 18.8%. Thus, the proposed method can effectively address the restrictive relation problem between permeability and energy loss in these composites. [Display omitted] [ABSTRACT FROM AUTHOR]

Considering the high-speed and high power density technical specifications of new energy vehicle motors, there is a growing demand for rotor strength as motor peak speeds reach 20,000 r/min and beyond. The utilization of non-oriented silicon steel with a high yield strength in rotors has emerged as a promising approach to increase motor speed. However, the magnetic and mechanical properties of high-strength silicon steel under variable temperature conditions have not been fully explored, particularly in regards to their impact on motor torque, efficiency, and speed. This manuscript investigates the behavior of high-strength silicon steel before and after annealing and at different temperatures, analyzing its influence on high-speed motor performance. The validity and feasibility of this study are confirmed through prototype testing, providing a comprehensive reference for engineering design. [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]

The variation rule of deformation structure and magnetic properties of high strength non-oriented electrical steel with cold rolling were studied by field emission scanning electron microscopy(SEM+EBSD), rapid temperature tube furnace and AC magnetic properties measuring instrument. The results show that the rough strips with a large number of substructures and smooth strips with a small amount of deformation are formed in cold-rolled high strength non-oriented electrical steel. The rough strip has a γ orientation, mainly {111}〈110〉, and the smooth strip has a {112}〈110〉 and {001}〈110〉 orientation. In the rough strips, there are a lot of shear bands with width of about 2-3 μm, which show an angle of 20°-35°to the rolling direction. And the quantity increases gradually with the increase of the reduction rate. There is a certain misorientation between the shear band and the matrix. With the increase of the reduction rate, the shear band gradually changes from {111}〈110〉 to {223}〈110〉, and the misorientation between the shear band and the matrix gradually increases. After annealing, the texture of Goss and {111} increases, while the texture of {001} decreases. The rolling direction magnetic induction intensity increases, the transverse magnetic induction intensity decreases, the magnetic anisotropy is significant, and the iron loss decreases.

Comprehensive Summary: Regulating spin crossover (SCO) behavior, especially controlling the spin transition steps, is an important scientific issue, mainly because people aim to control spin bistability and multistability. Presently, SCO bistability can be regulated by changing the ligand‐modifying species, non‐coordinated anions, guest molecules, and metal‐ion dopant. However, the control of multistability is extremely challenging, especially in Fe(III) SCO compounds. Here, we report that [FeIII(H‐5‐Br‐thsa)(5‐Br‐thsa)]·H2O (5‐Br‐thsa = (5‐bromo‐2‐hydroxybenzylidene)hydrazinecarbothioamide), a compound we have reported before, exists in two polymorphic forms: polymorph 1 exhibits three‐step SCO, and polymorph 2 shows five‐step SCO, with multi‐step SCO behavior effectively regulated by polymorphism. According to single‐crystal and powder X‐ray diffractometry, polymorphs 1 and 2 crystallize in different space groups during their spin transitions, with two‐step symmetry breaking observed (Pbcn → Pnc2 → Pbcn for polymorph 1; P21/n → Pn → P21/n for polymorph 2). We realized that the behavior of these two polymorphs depends significantly on the structure, including (i) the average Fe—N bond distance, (ii) deformation of octahedral FeIII atoms, and (iii) distinct crystal packing, which account for the large differences observed in magnetic properties. [ABSTRACT FROM AUTHOR]

Sm2Fe17N3 powder exhibits excellent magnetic properties but is unstable and decomposes into α-Fe and SmN phases at high temperatures. Therefore, the key to producing Sm2Fe17N3 bulk magnets is to reduce the deterioration of Sm2Fe17N3 powder during sintering. Herein, Sm2Fe17N3 bulk magnets were made using the spark plasma sintering (SPS) method with the addition of zinc stearate powder and zinc powder. Adding small amounts of zinc stearate powder and zinc powder improved the magnetic anisotropy and the coercivity of the magnets, respectively. The magnets produced by the SPS method using zinc stearate powder and zinc powder exhibited enhanced magnetic properties almost comparable to those of Sm2Fe17N3 powder. [ABSTRACT FROM AUTHOR]

A new molybdovanadate-based heterometallic complex, (NH4)17.5[Co0.5Na0.5(H2O)3]2[Co(H2O)4]2[(Cu6(H2O)2(OH)2V9Mo23O108)]·23.5H2O (1), was synthesized through the sequential-synthetic method and fully characterized. Structural analysis reveals that compound 1 exhibits a two-dimensional (2D) framework constructed from the C-shaped {V9Mo23Cu6} anions connected by [Co(H2O)4]2+ and [Co0.5Na0.5(H2O)3]1.5+ units. Compound 1 has a columnar structure with a smooth surface, sharp fringes, and an average size of 40 nm. Photophysical studies show that compound 1 has a band gap of ca. 2.13 eV. Magnetic studies reveal the presence of strong antiferromagnetic interactions in compound 1. A new molybdovanadate-based heterometallic complexes constructed from the C-shaped {V9Mo23Cu6} clusters linked with [Co(H2O)4]2+ and [Co0.5Na0.5(H2O)3]1.5+ units has been synthesized. Compound 1 has a band gap value of ca. 2.13 eV and exhibits the dominant antiferromagnetic behavior. [ABSTRACT FROM AUTHOR]

Bi1−xEuxFe0.95Co0.05O3 (x=0.05, 0.10, 0.15, and 0.20) nanoparticles were prepared through the sol-gel technique. Its structure, local electronic structure, magnetic and electric properties were systematically investigated. X-ray diffraction data show (104), (110) bimodal alignment and high angular migration, indicating that with the increase of Eu substitution at Bi site, the structure of BFO undergoes a continuous change in crystal structure. The hysteresis loop and the FC/ZFC curve show how magnetism varies with the size of the field and temperature. Finally, the causes of magnetic changes were analyzed by studying SXAS and hysteresis loops. [ABSTRACT FROM AUTHOR]

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry 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.)

Copyright of Rare Metals is the property of Springer Nature 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.)

Ferrite process exhibits promising potential as a technological solution for the treatment of chromium-containing wastewater, owing to its dual functionality in both purifying the wastewater and facilitating resource utilization. Nickel ions often coexist in chromium-containing electroplating wastewater because of the need for an electroplating process. When the ferrite process treats chromium-containing electroplating wastewater, coexisting nickel ions will enter the synthetic spinel crystals and affect their properties. In the study, the effects of nickel ions on properties of spinel synthesized in mixed wastewater containing chromium were investigated by atomic absorption spectroscopy (AAS), toxicity characteristic leaching procedure (TCLP), physical property measurement system (PPMS), and the effect mechanism was clarified by X-ray diffraction (XRD), toxicity characteristic leaching procedure (TCLP), scanning electron microscope (SEM) and energy dispersion spectrum (EDS).The findings suggested that the presence of nickel ions had minimal impact on both the quality of the filtrate and the stability of chromium in the products synthesized under room temperature conditions and an initial pH level of 12. Interestingly, it was observed that a moderate concentration of nickel ions significantly enhanced the magnetic properties exhibited by these products. However, excessive nickel ions resulted in a reduction in the magnetic properties of the synthetic solid substance. The crystallinity degree of the synthetic solid substance gradually degenerated as the reaction time increased. Compared to nickel ions, chromium ions more quickly entered the synthetic spinel structure. Finally, the stable nickel-containing spinel was formed when the reaction time was over 20 min, but the crystallinity degree of the synthetic solid substance was inferior. [ABSTRACT FROM AUTHOR]

The single crystals of the topological material candidate EuZnBi 2 have been grown using flux method, and the magnetic properties have been systematically investigated. Crystal structure analysis confirms that EuZnBi 2 crystallizes in a layered tetragonal structure at room temperature, consisting of alternating ZnBi 4 tetrahedral and Bi planar layers, separated by Eu atoms. The direct current (DC) magnetic susceptibility, alternating current (AC) magnetic susceptibility, and specific heat measurements indicate that a long-range antiferromagnetic order of Eu 2 + develops at T N = 20 K and the magnetic easy axis exists in the layers. It is interesting to note that EuZnBi 2 exhibits a magnetic anomaly below T N , which might be associated with the tilting of Eu moments and spin reorientation. [ABSTRACT FROM AUTHOR]

In order to study the electronic structure and magnetic properties of the non-rare earth based MnGa binary alloys under isostatic pressure, the crystal structure, formation, spin electronic structure as well as magnetic property of the tetragonal MnGa alloy under isostatic pressure of 500 MPa were systematically studied based on density functional theory calculation method. The results show that the tetragonal MnGa alloy can be formed easier, however the compressibility is anisotropic under the isostatic pressure of 500 MPa. The distances between heterogeneous species are smaller than that between the homogeneous species. The band structures are anisotropic and metallic. The Mn d states form higher net magnetic moment than that of the Ga d states in the MnGa alloy, and the Mn d states contribute to systematic remanent magnetism. The tetragonal MnGa alloy presents weak ferrimagnetism, its net magnetic moment decreases under 500 MPa. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office 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.)

The single crystals of the topological material candidate EuZnBi 2 have been grown using flux method, and the magnetic properties have been systematically investigated. Crystal structure analysis confirms that EuZnBi 2 crystallizes in a layered tetragonal structure at room temperature, consisting of alternating ZnBi 4 tetrahedral and Bi planar layers, separated by Eu atoms. The direct current (DC) magnetic susceptibility, alternating current (AC) magnetic susceptibility, and specific heat measurements indicate that a long-range antiferromagnetic order of Eu 2 + develops at T N = 20 K and the magnetic easy axis exists in the layers. It is interesting to note that EuZnBi 2 exhibits a magnetic anomaly below T N , which might be associated with the tilting of Eu moments and spin reorientation. [ABSTRACT FROM AUTHOR]

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 narrow bandgap, environment stability, and Pt vacancy‐induced magnetism, PtSe2 has been considered a promising candidate for future broadband photodetection and electronics. However, the growth of single‐crystal PtSe2 is still a challenge. Herein, the synthesis of hexagonal and tetragonal 2H─PtSe2 single‐crystal flakes by precisely tailoring the growth temperature is reported. Through atomic structure analysis, hexagonal and tetragonal flakes are proven c‐axis and a‐axis orientations of 2H─PtSe2, indicating the preferred nucleation orientations are along the basal plane and vertically basal plane, respectively. The crystalline orientation‐dependent properties are studied including high‐pressure and polarized in situ‐Raman, electrical transport. The out‐of‐basal plane vibration (A1g) is sensitive to pressure showing 2.744 and 3.282 cm−1 GPa−1 corresponding to c‐2H─PtSe2 and a‐2H─PtSe2, respectively. The conductivity of c‐2H─PtSe2 is 57 times higher than that of a‐2H─PtSe2. Furthermore, by studying magnetic transport at low temperatures, both c‐2H─PtSe2 and a‐2H─PtSe2 exhibit butterfly‐shaped magnetoresistance hysteresis suggesting their ferromagnetic property. The c‐2H─PtSe2 has a higher |MR| ratio and higher coercive field compared with a‐2H─PtSe2, indicating that across multilayer carrier regulation for c‐2H─PtSe2 is more difficult than intra‐layer carrier regulation for a‐2H─PtSe2. This study opens the way to grow different crystalline orientations of 2D materials and will bring more abundant properties. [ABSTRACT FROM AUTHOR]

Two isostructural mononuclear complexes of lanthanides (Ln = La and Pr) constructed from 1,8-naphthalene dicarboxylate (NDC) and 1,10-phenanthroline (Phen) as auxiliary ligand are reported. Both the complexes were formed through an in situ hydrolytic ring opening reaction of 1,8-naphthalic anhydride with Phen ligands. 3D supramolecular structures are observed which are guided by different weak interactions. The crystal structures of both the complexes were determined by single crystal X-ray diffraction. The room temperature photoluminescence studies, carried out in the powder state displayed three noticeable peaks from excited (3PJ; J = 2, 1, and 0) to ground state (3H4) at ~464 nm, 497 nm, and 538 nm, respectively, under UV excitation. Temperature dependent dc susceptibility (χ = M/H) as a function of temperature is investigated where Pr-complex shows antiferromagnetic behaviour. The Hirshfeld surface analysis of the two complexes is also described. [ABSTRACT FROM AUTHOR]

The aim of the present study is to investigate the effect of synthesis routes on phase evolution, microstructure, change in ionic state and their co‐relation with electrochemical charge storage, and magnetic properties of novel (CuNiFeMnCo)3O4 high entropy spinel oxide (HESO). We successfully synthesized novel (CuNiFeMnCo)3O4 HESO through two different synthesis methods, that is, sol‐gel and reverse coprecipitation methods abbreviated as SA‐1 and SA‐2, respectively. The XRD analysis for both samples reveals the formation of inverse spinel phase (space group Fd‐3m) with the lattice constant of 8.3602 and 8.2502 Å for SA‐1 and SA‐2, respectively. The sample synthesized through the sol‐gel method possessed porous morphology, whereas the sample synthesized through the reverse coprecipitation method had spherical particles. The x‐ray photoelectron spectroscopy confirmed the presence of +2 and +3 ionic states for Fe, Ni, and Co, while Cu has a + 2 state and Mn exist in +3 and +4 states for both the synthesized samples. The ionic states of all cations remain invariant irrespective of the synthesis methods. However, the concentration of oxygen vacancy is significantly different for samples synthesized through different routes. Both the HESO electrodes show the electrochemical double‐layer capacitive type behavior in 2 M KOH electrolytic solution. The value of maximum specific capacitance is 38.46 and 34.24 F/g at a scan rate of 5 mV/s for SA‐1 and SA‐2, respectively. Moreover, the electrodes have capacity retention of 90 and 99% for 1000 cycles at a scan rate of 50 mV/s for SA‐1 and SA‐2, respectively. The magnetic property of the synthesized HESO samples was also investigated, and the found values of magnetization and coercivity are 1.79 emu/g and 54.9 Oe and 8.5 emu/g and 67.69 Oe for SA‐1 and SA‐2, respectively. [ABSTRACT FROM AUTHOR]

Synthesis, structure, and magnetic properties of a tetranuclear metal complex with a symmetrical polydentate ligand, trans-(±)-1,2-(2-hydroxy-3-methoxybenzamido)cyclohexane (H2L), were characterized. The complexes have tetranuclear cubane cores with the formulae [Ni4(L)2(μ3-OMe)4(CH3OH)4] (1) and [Cu4(L)2(μ3-OMe)4(CH3OH)2] (2), whose cluster units are each composed of chiral ligands [(R, R)- or (S, S)-L]. The magnetic properties of the two compounds were characterized by 1 being ferromagnetic and 2 being antiferromagnetic. [ABSTRACT FROM AUTHOR]

Nanocrystalline BiFeO3 materials with multiferroic properties were successfully prepared using the solution-combustion method, and the impact of Ni-substitution in bismuth ferrite was investigated in the present research. Structural phase identification was done through XRD and FTIR spectroscopy. The average crystallite size was determined to be 44.87 nm for the pristine sample and 32.52 nm for the Ni-substituted ferrite. An enhancement in lattice strain, leading to crystal defects, was observed with Ni substitution in bismuth ferrite. Elemental analysis by EDX revealed the presence of Ni, Fe, Bi, and O in the substituted ferrites. FESEM studies indicated a significant decrease in the size of agglomerated and porous grains from 137 nm to 102 nm with the substitution of Ni in pristine bismuth ferrite. A considerable increase in the band gap from 2.21 eV to 2.39 eV was observed with Ni-substitution in the prepared ferrite phase, possibly due to the decrease in crystallite size. The very low coercivity (1.509 Oe) of pristine bismuth ferrite indicates its superparamagnetic behaviour. An improvement in saturation magnetization (almost two times) and a slight increase in coercivity (2.042 Oe) were found with Ni-substitution at Fe3+ sites in bismuth ferrite compared to the pristine ferrite. At 10 KHz, Ni-substitution enhanced the dielectric constant and decreased the dielectric loss of the prepared bismuth ferrite materials. Ferroelectric investigation of the prepared ferrites indicated an improvement in the P-E loop of Ni-substituted bismuth ferrite with a reduced loop area, indicating low electrical leakage.

This study investigated the effects of uniaxial tensile strain on the magnetization process of an Fe-9wt%Ni (9Ni) alloy to increase understanding of its magnetic behavior. As the applied strain was increased from 0 to 14 %, the magnetization curve changed remarkably, particularly under a high-intensity magnetic field, and magnetic flux density, relative permeability, remanence, and coercive force degraded significantly, especially at strains greater than the upper yield point. Increase in tensile strain caused increase in hysteresis losses, primarily because strain induced crystal defects, which affected the rearrangement of magnetic domains. Increased dislocation density was the primary contributor to the observed deterioration in magnetic properties; changes in texture and phase had little influence. This finding indicates that strain-induced deformation strongly affects the magnetic behavior of 9Ni alloys; this insight will be useful in research aimed at mitigating welding defects such as arc blow, that are attributed to the magnetization of Ni steel.

Electrospinning technology is widely used for preparing biological tissue engineering scaffolds because of its advantages of simple preparation, accurate process parameters, and easy control. Poly(L-lactide) (PLLA) is regarded as a promising biomass-based polymer for use in electrospinning. The incorporation of Fe3O4 nanoparticles (NPs) could improve the osteogenic differentiation and proliferation of cells in the presence or absence of a static magnetic field (SMF). In this work, these two materials were blended together to obtain electrospun samples with better dispersibility and improved magnetic properties. First, composite PLLA and Fe3O4 NP fibers were prepared by means of electrospinning. The influence of electrospinning conditions on the morphology of the composite fibers was then discussed. Changes in magnetic properties and thermal stability resulting from the use of different PLLA/Fe3O4 mass ratios were also considered. Next, the morphology, crystal state, thermodynamic properties, and magnetic properties of the electrospun samples were determined using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and vibration sample magnetization (VSM). The results showed that the fibers prepared using PLLA with Mn = 170,000 exhibited good morphology when electrospun at 12 KV. The magnetic properties of PLLA/Fe3O4 composite electrospun fibers increased with the NP content, with the exception of thermal stability. The results of the present study may help to promote the further development of PLLA/Fe3O4 composite materials in the biomedical field.