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The cobalt-based full Heusler alloy Co2MnGa (CMG) is well known for exhibiting an exotic phenomenon such as magnetic Weyl semimetallic nature with a high Curie temperature of ∼700 K and a giant anomalous Hall effect. Here, we report a detailed study of structural, electrical, and magnetic properties of Co2MnGa thin films (thickness in the 40–10 nm range) grown on Si(100) by the direct-current magnetron co-sputtering technique using Co and MnGa targets. Structural analysis of the samples revealed the polycrystalline nature of these films with B2 type structural ordering. The damping parameter decreases with the increase in film thickness and reaches the minimum value of 6.1 × 10−3 for a 40 nm thin CMG film. These CMG films are magnetically isotropic and soft ferromagnetic in nature. A remarkably high value of anomalous Hall conductivity (AHC) of 1920 S/cm (2 K) is found for the 40 nm thin film, which is comparable to earlier reported values on highly ordered CMG films. Nearly 73% of this AHC value originates from the intrinsic contribution. The AHC and longitudinal conductivity both increase with the film thickness. Different scaling mechanisms are used to compute the intrinsic and extrinsic contributions playing a role in AHC. The analysis of advanced scaling [by Tian et al., Phys. Rev. Lett. 103, 1–4 (2009)] performed on these CMG films suggests the consistency in the enhanced intrinsic AHC value irrespective of the thickness and a decrease in skew scattering contribution with thickness. These results will enhance the understanding about the magnetic and transport properties of Co2MnGa thin films of different thicknesses and suggest it to be a promising material for topospintronic applications. [ABSTRACT FROM AUTHOR]

The largest ever set, RotGT-2023, of statistically validated experimental components of rotational g tensors and respective vibrational corrections, has been created. The experimental values were collected from literature data. The vibrational corrections for obtaining equilibrium molecular g values have been calculated at the highest affordable coupled cluster level of theory. The set comprises 278 parameters from 129 molecules, including their isotopologues. Statistical assessment of the data has been performed to exclude unreliable parameters. A benchmarking of two theoretical approximations, based on coupled cluster and density functional theories, has been performed. The determined weighted mean and weighted standard deviations of the relative errors in calculated equilibrium g values are 1.09% and 2.07% for the ae-CCSD(T)/x2c-TZVPPall-s//ae-CCSD(T)/cc-pwCVTZ level. The obtained results can be used for predicting the rotational Zeeman effect, correcting rotational constants in spectroscopic studies and in molecular structure refinements. The latter has been demonstrated on the refinement of the molecular structure of silane SiH4, which resulted in r e se (Si–H) = 1.473 323 1(27) Å. The other tested theoretical protocol, PBE0/x2c-TZVPPall-s//PBE0-D3BJ/def2-QZVPP, showed considerably worse statistical properties. The RotGT-2023 data set and the developed in this work statistical model are recommended for benchmarking of theoretical approximations for calculations of molecular magnetic properties. [ABSTRACT FROM AUTHOR]

L10-MnAl exhibits excellent magnetic properties and could be used as a candidate to fill the gap between hard ferrite and rare-earth based permanent magnet (PM) applications. However, one of the major problems with L10-MnAl is that the structure is metastable and decomposes to other structural phases at higher temperature. Therefore, enhancing the structure stability of L10-MnAl is essential for PM applications. We studied the prospect of improving the structural stability and increasing the uniaxial magnetic anisotropy energy (K u) of the L10-MnAl structure in this work. It is found that C-doping at the 1d interstitial site enhanced the structure stability of the compound. Moreover, Fe substitution on Mn sites shows a significant increase in the uniaxial magnetic anisotropy energy (K u). Therefore, the electronic structure and magnetic properties of L10-ordered Mn1−xFexAlC (x = 0, 0.125, 0.250, 0.375, 0.50, 0.625, 0.75, and 0.87) alloys are investigated by using the first-principles calculations. The results show that x = 0.375 Fe content in the L10-MnAl alloy and 6% doping of C maintained the structural stability and provided a maximum value of K u = 2.13 (MJ/m3), which is 25% higher than for the pristine L10-MnAl, making it suitable for permanent magnet applications. [ABSTRACT FROM AUTHOR]

We report on the thermal and magnetic properties of D y 1 − x S c x N i 2 series compounds (x = 0.1 , 0.3 , 0.5 , and 0.7), which were investigated through a model Hamiltonian including the exchange, Zeeman, and crystalline electric field interactions. We investigated the effect of Sc substitution on the Dy site on the magnetic and magnetocaloric properties of these compounds. Theoretical results were simulated for heat capacity, entropy, and the magnetocaloric effect quantities. Our model reproduced the decrease of the magnetic ordering temperature and of the isothermal entropy change peaks as Sc concentration increases. Our theoretical results were confronted with experimental data from the literature, showing good agreement. [ABSTRACT FROM AUTHOR]

Giant magnetostrictive material (GMM) is well known for its hysteresis behaviors related to multiple influencing factors, such as bias magnetic field and excitation level. This feature greatly challenges the loss prediction of giant magnetostrictive transducers. The existing loss prediction models need further improvement to cover the sensitive magnetic properties of GMM. In this paper, the variations of the iron losses with the operation conditions are interpreted by the variations of the Jiles–Atherton model parameters, and a concise parameter identification procedure with great generalizability is proposed. The iron losses of Terfenol-D under variable excitation levels and the DC biases are further investigated. With the proposed procedure, the introduced eight additional modification parameters for the original Jiles–Atherton model are easy to obtain, and merely a few hysteresis loops of Terfenol-D are involved. An experimental setup is established for further demonstration. Comparisons between the measured and calculated results indicate the effectiveness of the proposed approach. Throughout the bias-excitation space within the frequency range under investigation, the iron losses can be precisely estimated with an acceptable error of less than 5%. [ABSTRACT FROM AUTHOR]

Magnetocaloric properties of TbCrO3 and TmCrO3 are reported and compared with those of the previously reported rare-earth chromites RCrO3 (R = Gd, Dy, Ho, and Er) and other perovskite-type oxides. The samples of TbCrO3 and TmCrO3 in this work were synthesized using a citrate gel combustion technique, and their magnetic properties were investigated and compared with those reported previously on RCrO3 (R = Gd, Dy, Ho, and Er). The Cr3+–Cr3+ ordering temperatures were found to strongly depend on the ionic radii of the rare-earth. By fitting the dc magnetization data with modified Curie–Weiss law including the Dzyaloshinsky–Moriya antisymmetric exchange interaction (D) and the symmetric exchange constant Je, spin canting angles (α) were obtained. In general, α was found to increase with the decreasing ionic radii of R3+ in RCrO3. The magnetocaloric properties investigated included the magnetic entropy change (−ΔS) for a given change in magnetic field (ΔH), the corresponding adiabatic temperature change (ΔTad), and their relative variations (ΔTad/ΔH) and (−ΔS/ΔH). It is observed that for RCrO3, (−ΔS) measured in the vicinity of the ordering temperature of R3+–R3+, varies almost as G2/3 where G is the de Gennes factor. Among RCrO3, GdCrO3 shows the largest value of (−ΔS/ΔH), because of its largest G factor and its magnitudes of (ΔTad/ΔH) and (−ΔS/ΔH) compare well with the reported values for the perovskites GdFeO3 and EuTiO3. These comparisons presented here provide useful information on the potential use of these materials in magneto-refrigeration technology. [ABSTRACT FROM AUTHOR]

We report a large cryogenic magnetocaloric effect stemming from an unconventional borderline first-order magnetic phase transition with negligibly small thermomagnetic hysteresis in a rare-earth-based intermetallic compound PrNdIn. The sample exhibits maximum magnetic field-induced entropy change as large as −10 J/Kg K (for 20 kOe magnetic field change) near the boiling point of oxygen. Magnetocaloric properties of PrNdIn are comparable to those of other known potential magnetocaloric materials with operating temperatures ranging between 50 and 125 K. The magnetic properties of the present sample are qualitatively reminiscent of those of the binary Pr2In and Nd2In, including the emergence of a second low-temperature anomaly in the temperature dependence of magnetization. [ABSTRACT FROM AUTHOR]

Investigating high-performance and stable spintronics devices has been a research hotspot in recent years. In this paper, we employed first-principles methods and Monte Carlo (MC) simulations to explore the structure, electronic, and magnetic properties of monolayer NbSe2, as well as its behavior under carrier concentration modulation. The research on the electronic structure reveals that by introducing an appropriate amount of holes, the material can undergo a transition from metal to a half-metal state, achieving 100% high spin polarization. Investigation of magnetic crystalline anisotropy shows that the magnetic crystal anisotropy energy of 1210 μeV in out-of-plane is beneficial to maintain ferromagnetic order at high temperatures. In addition, doping with suitable carriers can effectively enhance or strengthen the ferromagnetic coupling in NbSe2 so that the magnetization easy axis is shifted. This reveals the potential application prospects of NbSe2 in electronically controlled spintronic devices. Analysis of the Fermi surface shows that both holes and electron doping increase the Fermi velocity of the material. The effect of hole doping is particularly significant, indicating its potential application in Fermi velocity engineering. Under the theoretical framework of the extended two-dimensional Ising model, based on MC simulation, the Curie temperature (TC) of NbSe2 is predicted to be 162 K. The effects of carrier concentration and the magnetic field on the magnetic and thermal properties of monolayer NbSe2 are simulated. The results show that appropriately increasing the hole doping concentration and magnetic field is conducive to obtaining ferromagnetic half-metallic materials with TC higher than room temperature, which provides theoretical support for experimental preparation. [ABSTRACT FROM AUTHOR]

FePBNbCr amorphous soft magnetic composites (SMCs) with high compaction density (ρ c) and commendable magnetic properties were successfully fabricated via low-pressure hot-compacting at 160 MPa. Due to the thermoplastic properties of amorphous powders in supercooled liquid region (Δ T x), the hot-compacting in the Δ T x is conducive to the increase of ρ c for the amorphous SMCs, thereby improving the corresponding soft magnetic properties via reducing the number of pinning sites. Compared with these of the cold-compacted amorphous SMCs at 600 MPa, the ρ c increases by 20.3 % to 6.04 g/cm3, the effective permeability increases by 5.26 times to 95.3, while the corresponding total core loss decreases 74.5 % to 154.4 kW/m3 (100 kHz, 0.05 T) for the amorphous SMCs hot-compacted at 495 °C with a pressure holding time of 6 min. These results indicate that the low-pressure hot compacting is an effective measure to further improve soft magnetic properties of the amorphous SMCs for rapidly adapting to the development needs of high-frequency and miniaturization of electronic devices. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the impact of adding the Ni 50 Mn 37 Sn 10 Cu 3 alloy to a Ni 0.1 Zn 0.9 O ceramic matrix on structural, morphological, magnetic, thermoresistive, and thermoelectric properties. The Ni 0.1 Zn 0.9 O system was obtained through the combustion reaction method. The microcomposite (Ni 0.1 Zn 0.9 O) 1-x (Ni 50 Mn 37 Sn 10 Cu 3) x , where x = 0, 2.5, 5, 10, 20, and 40, was successfully with sintering at 1223K. The microcomposite samples exhibited a good linear relationship between the logarithm of electrical resistivity (lnρ) and the reciprocal of absolute temperature (1000/T) at 300K–360K. The values of the constants A, B, and C are characteristic of NTC behavior, and their curves closely approximate the experimental data. The resistivity ρ 305 , and the coefficients β, α, and SF obtained from the thermistors are approximately 0.12 MΩcm to 7.28 MΩcm, 5026 K–8436 K, 0.017 K-1 to 0.024 K-1, and 1.03 to 1.4, respectively. The magnetic properties of the samples increased as the alloy addition content increased, with values ranging from 51.7 to 63 for H c , 0.03 to 1.34 for M s , and 2∙10−4 to 0.13 for M r. The values of the band gap remained in the range of 2.23–2.77 eV. The magnetic, thermoelectric, and thermoresistive characteristics can be adjusted to the desired value by altering the content of Ni 50 Mn 37 Sn 10 Cu 3 in the Ni 0.1 Zn 0.9 O matrix. The results demonstrate the potential of the studied system for NTC performance materials, with magnetic and thermoelectric properties. There is significant potential for the development of new microcomposite materials, but it also opens up new research perspectives in the field, especially related to microcomposites containing Heusler alloys. [ABSTRACT FROM AUTHOR]

Recent advancements in high entropy oxides (HEOs) have sparked significant interest as a promising frontier in materials research, revolutionizing the landscape of material design and properties. They exhibit outstanding stability, intriguing functional properties, and unparalleled design flexibility enabled by the inclusion of multiple cations in these materials. In this study, we successfully stabilized several new high entropy spinel oxides with compositions (Ni 0.2 (Mg/Mn) 0.2 Co 0.2 Cu 0.2 Zn 0.2)B 2 O 4 (B = Al, Ga, Mn). The room temperature X-ray diffraction (RT-XRD), field emission scanning electron microscopy (FE-SEM), and energy dispersive spectroscopy (EDS) measurements highlight the crystal structure of the materials with excellent chemical homogeneity at the micro-scale. RT-XRD and Raman spectroscopy confirmed the formation of single-phase cubic spinel structures. However, the Mn-based sample exhibited tetragonal distortion. Magnetic measurements show remarkable variation in the magnetic properties: (Ni 0.2 Mg 0.2 Co 0.2 Cu 0.2 Zn 0.2)Mn 2 O 4 shows complex ferrimagnetic behavior, Al and Ga based diamond lattice (Ni 0.2 Mg 0.2 Co 0.2 Cu 0.2 Zn 0.2)B 2 O 4 (B = Al and Ga) materials revealed extremely high magnetic frustration and absence of magnetic ordering down to 1.8 K, indicative of exotic frustrated state. Magnetic transitions (spin-glass like) are observed in (Ni 0.2 Mn 0.2 Co 0.2 Cu 0.2 Zn 0.2)B 2 O 4 (B = Al and Ga) materials. Our study highlights the potential to finely tune the magnetic responses through compositional engineering, thus paving the way for the development of tailored magnetic materials for various applications. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper investigated the impact of Co ions doping on the structure, magnetic properties, and magnetocaloric effect for La 0.8 Sr 0.2 Mn 1- x Co x O 3 ceramics (LSMCO) by sol-gel method and first-principles calculations The use of first-principles calculations was provided for subsequent experiments. The sol-gel preparation of LSMCO ceramics and sintered at 950 °C for 10 h. It was shown that the samples' cell volume and lattice constants changed slightly with increasing Co2+ doping but remained a rhombohedral structure (No.167, R-3c space group) by statistics of TEM and XRD. The average particle size for the LSMCO ceramics ranged from 130 nm to 170 nm. LSMCO's chemical composition was verified by EDS and XPS and it was demonstrated that Co2+ was successfully doped. The oxidation state of La was found to be +3, Mn is a mixture of Mn3+ and Mn4+ valence states, and Co is a mixture of Co3+ and Co2+ valence states using XPS. In the vicinity of Tc, all samples presented the second-order magnetic phase transition from ferromagnetic to paramagnetic resorting to normalization and the Banerjee criterion. The Tc dropped from 292 K to 237 K with increasing Co2+ doping. The blocking temperature and the saturation magnetization were suppressed by the Co2+ substitution while the maximum magnetic entropy change of the LSMCO ceramics was observed to reduce as Co2+ increased. When the external magnetic field is 5 T, the La 0.8 Sr 0.2 Mn 0.95 Co 0.05 O 3 ceramics has a Tc of 292 K and a maximum magnetic entropy change value of 3.47 J/(kg K). [ABSTRACT FROM AUTHOR]

The article presents a comprehensive investigation of the crystal structure, impedance spectra, magnetic, magnetodielectric, and magnetoresistive properties of (1- x)CoFe 2 O 4 – x PbTiO 3 composites with varying concentrations (х = 0, 0.2, 0.4, and 0.6). The study also examines the effects of applying a uniaxial pressure of 1 GPa to the synthesized powders using Bridgman anvils. Our findings reveal that the synthesis of these composites results in the formation of an additional phase, lead hexaferrite PbFe 12 O 19 , which exhibits multiferroic properties. Additionally, the coherent scattering region of the components is significantly reduced after mechanical activation. Notably, the real part of the resistivity ρ ′(ω) of nanostructured CoFe 2 O 4 ceramics increases eightfold at T = 240 °C. The composites demonstrate significant magnetoresistance at room temperature, reaching up to 250 %. The study also reveals that the signs of the magnetodielectric MD (B) and magnetoresistive coefficient MR (B) vary with the frequency of the measuring field for certain concentrations. Using the first-order reversal curve (FORC) method, it was observed that after nanostructuring CoFe 2 O 4 through mechanical activation, the interaction field H u shifts from ± 0.6 kOe to ± 0.8 kOe, while the coercive field H c increases from 1.05 kOe to 5 kOe. Moreover, the two-dimensional FORC maps of the composites show increased complexity, due to the formation of additional magnetic phases. [ABSTRACT FROM AUTHOR]

The physicochemical properties of NZFO/f-MWCNTs composites based on 5 wt% of Ni 0.5 Zn 0.5 Fe 2 O 4 (NZFO) nanoparticles and functionalized multi-walled carbon nanotubes (f-MWCNTs) synthesized via ex-situ method are presented. The influence of annealing on the as-received hybrids is discussed. The structural and microstructural analysis confirms the efficiency of the synthesis process. The slight redistribution of cations over tetrahedral and octahedral sites is noted by Raman and X-ray photoemission (XPS) studies. The NZFO crystallite size is almost stable over sample processing, but the presence of single particles, clusters and aggregates on the f-MWCNTs' surface is proven. The XPS spectra comparison reveals the domination of nanotubes as designed. The deconvoluted Fe2 p lines confirm the iron redistribution slightly modified by annealing. The magnetic properties analysis revealed the cluster-glass state of NZFO particles. The core-shell-like structure with a magnetic core and disordered layer is evidenced. The influence of Fe-based carbon matrix residues in all hybrids was detected. [ABSTRACT FROM AUTHOR]

Augmentation of optical and magnetic properties of ZnO system via mono- and co-doping is an efficient approach to achieve enhanced ferromagnetism and photocatalytic activity. In this scenario, we made an endeavor to prepare the nanocrystalline ZnO, ZnO:Eu, and ZnO:(Eu, Er) samples through a co-precipitation technique. Structural analysis ruled out the effectual substitution of Eu and Er in the ZnO lattice without disturbing the original structure. Both ZnO:Eu and ZnO:(Eu, Er) NPs exhibited lower optical band gap values than pure ZnO. In M − H studies at room temperature, ferromagnetic behavior was observed in ZnO, ZnO:Eu, and ZnO:(Eu, Er) NPs. Expectedly, ZnO:(Eu, Er) NPs showed highest H 2 evolution than both ZnO and ZnO:Eu NPs beneath solar spectrum. The possible roots behind the extended H 2 production are discussed in detail. Hence, ZnO:(Eu, Er) NPs may find in applications is photocatalysis and spintronics. [ABSTRACT FROM AUTHOR]

Magnetic nanocomposite was prepared using the wet chemical precipitation approach with varying amounts of cobaltous oxide (CoO). The concentrations of CoO were 0.5, 3.5, 6.5, and 9.5 g per 100 % wollastonite composition. Samples were sintered separately at 1000 and 1200 °C. X-ray diffraction analysis (XRD) of the sintered parent sample revealed the formation of wollastonite CaSiO 3 and larnite Ca 2 SiO 4 , as well as a minor silicon oxide SiO 2 phase. In CoO-doped samples, Co-åkermanite Ca 2 CoSi 2 O 7 and other phases were formed. The XRD and scanning electron microscope SEM confirm the samples' submicron and nanocrystalline microstructure. The Fourier transform infrared spectroscopy (FTIR) and Raman spectra (RS) of investigated samples sintered at 1000 and 1200 °C revealed their bond structure. Both analyses confirmed that incorporating CoO into CaSiO 3 significantly improved its vibrational modes, reflecting structural modifications. By increasing the cobalt oxide content from 3.5 to 9.5 wt%, the samples attain the ideal paramagnetic state, as demonstrated by the magnetic hysteresis (M − H) curve, which is linearly reversible. Formation of the Ca 2 CoSi 2 O 7 significantly alters the magnetic characteristics of the samples, whether through increasing the cobalt oxide concentration up to 9.5 wt% or modifying the sintering temperature. This enables the prepared nonocomposites to be suitable for novel magnetic applications. [ABSTRACT FROM AUTHOR]

In this work, the effects of SrCO 3 and Fe 2 O 3 particle size on the reaction process, morphology and magnetic properties of M-type strontium hexaferrites (SrM) have been further studied. Pure strontium hexaferrite magnetic sample based on SrCO 3 and Fe 2 O 3 molar ratio of 1:6 has been successfully prepared at 1150 °C. The results indicated that Fe 2 O 3 particle size was the main factor of affecting the formation of SrM, a pure SrM phase magnetic sample was able to obtain at lower calcination temperatures by using fine Fe 2 O 3 powder as raw material, and at the same calcination temperature, a sample using fine Fe 2 O 3 powder as raw material was able to obtain pure SrM phase magnetic sample with shorter holding time. When the mean particle size of Fe 2 O 3 was below 60 nm, a pure SrM phase magnetic sample was able to form at 1150 °C at a molar ratio of 1:6 of SrCO 3 and Fe 2 O 3. In this case, the magnetic parameters of the sample with the optimum magnetic parameters were saturation magnetization M S = 77.8 emu/g and coercive force H C = 4122 Oe. And the solid-state reaction process of the corresponding samples was slightly faster when the mean particle size ratio of Fe 2 O 3 and SrCO 3 was between 0.35 and 0.36. Assuming that a SrCO 3 particle is surrounded by Fe 2 O 3 particles, it can be inferred that the corresponding molar ratio of Fe and Sr of the nearest raw material particles is between 3.6 and 3.8. [ABSTRACT FROM AUTHOR]

This paper presents an investigation into the structural, magnetic, and dielectric characteristics of BaFe12-xYxO19 (x = 0.0, 0.2, 0.4, 0.6) nanoparticles (NPs) produced by the sol-gel method at 800, 900, 1000, 1100 °C annealing. Rietveld refinement analysis shows that the lattice parameter ratio (c/a) lies within the range of 3.93–3.96 provides the confirmation of M type hexaferrite with space group P 6 3 / mmc. The average crystallite size for BaFe 12 O 19 is found to decrease (53.0–23.4 nm) with increasing annealing temperature while for doped BaFe 12-x Y x O 19 it is increased from 30.7 to 96.2 nm. The magnetization found to decrease (82–17 emu/g) with Y3+ content for 800 and 900 °C annealing. However, for 1000 and 1100 °C annealing the magnetization increases and reaches to maximum 100.2 emu/g for x = 0.2 at 1100 °C annealing. The site preference of the Fe3+ ions is responsible to change the value of magnetization. The coercivity of undoped BaFe 12 O 19 varies from 4039 to 2028 with doping content. However, maximum coercivity 4586 Oe is found for x = 0.4 at 900 °C. The dielectric function is found to vary with annealing temperature and Y content as well. The wide range of magnetic properties (soft and hard magnetic) can be used in data storage, spintronic and microwave device applications. [ABSTRACT FROM AUTHOR]

High-entropy perovskite ceramics (HEPCs) with equal atomic ratios have recently emerged as a highly promising class of materials due to their unique magnetic properties. However, the crystal structure, microstructure and magnetic properties of unequal atomic ratios HEPCs have yet to be fully investigated. In this paper, single-phase HEPCs (La 0.25 Nd 0.25 Sm 0.25 Gd 0.25) 1- x Ho x MnO 3 ((LNSG) 1- x H x MO) have been synthesized using solid-state reactions. The effect of Ho element content (x = 0.25, 0.3, 0.35 and 0.4) on the structure and magnetic properties was systematically investigated. All samples exhibit an orthorhombic perovskite structure with a Pbnm space group and show obvious crystallization characteristics after sintering at 1250 °C for 16 h (LNSG) 1- x H x MO HEPCs display a smooth surface texture and distinct grain boundaries, as well as significant hysteresis effects at T = 5 K. The spin-orbit interaction and magnetic anisotropy between Ho and Mn ions increase with the increase of Ho content, which increases the saturation magnetization (M s) of HEPCs. (LNSG) 0.6 H 0.4 MO exhibits the lowest magnetic hysteresis losses among the considered samples, attributed to its highest M s (50.95 emu/g) and the lowest coercivity H c (0.6 kOe). These characteristics endow it with a potential application in magnetic storage devices. [ABSTRACT FROM AUTHOR]

The present work reports a synthesis of octahedron (A55NO) and cube-shaped (A55NC) Mn 0.5 Zn 0.5 Fe 2 O 4 ferrite nanoparticle dispersion in distilled water. The crystal structure analyzed using powder X-ray diffraction (XRD) shows the crystallite sizes of 17.7 ± 0.4 nm and 11.9 ± 1.0 nm, respectively, for the A55NO and A55NC particles. The morphology as seen from transmission electron microscopy (TEM) confirms 17.8 ± 0.3 nm (σ = 0.27) and 8.7 ± 0.3 nm (σ = 0.33) edge lengths, respectively, for octahedron and cube-shaped particles. The thermogravimetric analyzer (TGA) and Fourier transform infrared (FTIR) spectroscopy are used to confirm the chemical binding of the surfactant with a sharp transition at 208.67 °C and 218.32 °C, respectively, for octahedron and cube-shaped particles, indicating the removal of the surfactant due to its decomposition from the particle surface. Both the particles are highly magnetic and have 75.32 Am2/kg and 72.93 Am2/kg saturation magnetization, as revealed by their M − H loops using a vibrating sample magnetometer (VSM). The stability of the sample is confirmed using the particle size analyzer (DLS) and the Zeta potential analyzer. The induction heating capacity of the fluid was investigated using the Embrell Easy Heat model LA6310 at 330 kHz. The heating response shows that even a minimum concentration of 1 mg/mL is sufficient to achieve the hyperthermic window temperature of 42 °C for both samples, which, unlike the same composition prepared by other routes, makes it impossible to go beyond 38 °C. Moreover, octahedron particle dispersion can reach this window temperature within 10 min, whereas cube particle dispersion requires only 15 min. The findings of this study hold significant practical value since it confirms that Mn 0.5 Zn 0.5 Fe 2 O 4 composition with tuneable shape has the potential to work as a temperature-controlled magnetic switch for magnetic fluid hyperthermia under the defined safety limit with the minimum concentration. [ABSTRACT FROM AUTHOR]

This paper presents a study on the microstructure and magnetic properties of LaCoO 3 (LCO) thin films, and also the micropatterning of LCO thin films using a novel photo-sensitive sol-gel lithography method. It is found that higher heat-treatment temperature can promote the healing of cracks and filling of pores, resulting in refining the grains, and improving the density of LCO film. The film treated at 850 °C has a larger nucleation energy, which makes the distribution of nucleation sites more uniform, promoting the healing of cracks and filling of pores, refining the grains, and improving the density of LCO film. LCO precursor sol, metal chelates with UV photosensitivity were synthesized by adding BzAcH photosensitizer. LCO micro-arrays with diameters of 50 μm, as well as other fine patterns with a minimum line width of about 2 μm were successfully prepared by a UV mask lithography technique. In contrast, our novel lithography method eliminates the need for photoresist, as the fine pattern is formed during the preparation of the LCO gel film, which is the advantages of our lithography method over traditional techniques. [ABSTRACT FROM AUTHOR]

This study reports the synthesis and characterization of nanocrystalline Ni 0.5 Co 0.2 Zn 0.3 Bi x Fe 2-x O 4 (x = 0.00, 0.025, 0.050, 0.075, 0.100) ferrites synthesized via the sol-gel auto combustion method. The structural, morphological, electric, dielectric, and magnetic properties of Bi3+-doped Ni–Co–Zn spinel ferrites annealed at 700 °C and further sintered at 850 °C, have been investigated towards analyzing the effect of Bi3+ doping. X-ray diffraction (XRD) patterns and Fourier Transform Infrared Spectroscopy (FTIR) spectra have revealed the single-phase cubic-spinel structure of all inspected materials while retaining their high crystalline nature. Their average crystallite size and average grain size are found in the nanoscale range (48–74 nm) and (46–67 nm), respectively. The saturation magnetization (M s) and experimental magnetic moment (η exp) are found to decrease with increasing Bi3+ content. The samples sintered at 850 °C display higher AC resistivity, attributing to the reduction of electrons hopping through grains in the samples. The low coercivity values (23.68–87.71 Oe) are observed, classifying the investigated materials as soft ferromagnetic. The increased magnetic anisotropy (K) through Bi3+ doping indicates tunable stability in magnetic orientations, making them suitable for spintronics applications. [ABSTRACT FROM AUTHOR]

In this study, a CoFe 2 O 4 (CFO)/La 0.7 Ca 0.3 MnO 3 (LCMO) polycrystalline bulk was selected as representative material. Pressure (P) was applied during the magnetic measurements to tune the interparticle distance for changing exchange coupling (EC), dipolar interaction (DI), and anisotropy (K). Further, the effects of these factors on the magnetic properties of the composite magnet were investigated, and the main results are as follows. At ambient pressure, a step-like spontaneous magnetization is observed due to the difference in anisotropy between the particles. The magnetic transition temperature of LCMO in the composite is lower than that of the pure LCMO due to the lattice mismatch and the Co(Fe)–O–Mn super-exchange interaction occurring at the interface between CFO and LCMO. In the low temperature region, the pressure reduces the magnetization, due to the enhanced distortion of MnO 6 octahedra in LCMO, induced extra anisotropy and the enhanced DI by the pressure. The coercivity of the composite at 10 K increases monotonically with pressure due to the pressure-induced anisotropy, while the remanence magnetization-to-saturation magnetization ratio (M r / M s) decreases with pressure. This is attributed to (i) the reduced M r caused by the enhanced distortion of the Mn3+O 6 octahedra and the pressure-induced anisotropy, and (ii) the larger M s of the composite with respect to that of the pure CFO. Briefly, compared with the single-phase magnetic material, variation in the magnetic properties of the composite magnet with temperature, magnetic field, and pressure exhibits more complex behaviors. Moreover, several factors should be considered for the related mechanisms, such as the effects of pressure on the inter-grain EC and DI, pressure-induced anisotropy, distortion of the Mn3+O 6 octahedra in manganite, lattice mismatch, and EC at the interface. These results provide an experimental reference for understanding the mechanism that accounts for the magnetic properties observed in composite magnets, which can promote their practical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Samarium doped Ni-Zn ferrites (Ni 0.5 Zn 0.5 Sm x Fe 2-x O 4) were synthesized using sol-gel auto-combustion technique with Sm3+ doping concentrations varying as x = 0.00, 0.05, 0.10, 0.15, and 0.20. The prepared nanomaterials were examined using X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), complex impedance spectroscopy (CIS) and vibrating sample magnetometer (VSM). The XRD examination verified the pure FCC spinel phase of all samples with no impurity peak. The FTIR analysis for spinel molecules formation identified two frequency bands at the octa and tetrahedral sites. The TEM analysis confirmed the shape, size and distribution of prepared nanoparticles. The different dielectric properties were analyzed with a frequency range of 1 MHz–3 GHz and the impact of doping was also studied simultaneously. Magnetic nature of prepared materials was investigated at room using the VSM. It is found that the prepared nanomaterials are suitable for high energy storage as well as magnetic applications. [Display omitted] • Samarium doped (Ni 0.5 Zn 0.5 Sm x Fe 2-x O 4) nanoparticles were synthesized via sol-gel technique with Sm3+ (0.00 ≤ x ≤ 0.20). • The effect of Samarium on structural, dielectric and magnetic properties were investigated. • The structural parameters such as lattice constant, crystallite size, lattice strain, micro-strain were determined. • Frequency (range: 1 MHz to 3 GHz) dependent dielectric, impedance, and electric modulus properties were investigated. • Saturation magnetization, coercivity, retentivity and anisotropy constant were determined. [ABSTRACT FROM AUTHOR]

Pyrochlore oxides, specifically G d 2 Z r 2 O 7 , have been a subject of interest due to their unique structural, physical, and magnetic properties. These properties make pyrochlore oxides potential candidates for various technological applications, including magnetocaloric refrigeration. Magnetocaloric refrigeration is a promising alternative to conventional refrigeration methods, as it is more energy-efficient and environmentally friendly. By studying the magnetocaloric effect of pyrochlore oxides like G d 2 Z r 2 O 7 , researchers can gain a deeper understanding of the underlying mechanisms and potential applications of these materials in magnetocaloric refrigeration systems. By employing advanced computational methods such as Monte Carlo simulations and first-principles calculations based on the full-potential linearized augmented plane wave (FP-LAPW) a technique is employed to examine the magnetic structure, researchers can investigate the magnetocaloric effect of pyrochlore oxides with high accuracy and precision. This information has the potential to aid in the advancement of more effective magnetocaloric systems materials and ultimately lead to the design and optimization of advanced magnetocaloric refrigeration systems. [ABSTRACT FROM AUTHOR]

This study focuses on examining how the rare-earth cerium incorporation affects the magnetic, dielectric, and mechanical characteristics of Ni 0.5 Mn 0.25 Co 0.25 Ce x Fe 2-x O 4 spinel ferrite nanoparticles. (NMCCF). The nanoferrite Ni 0.5 Mn 0.25 Co 0.25 Ce 0.04 Fe 1.96 O 4 acquires the lowest coercivity of 567 Oe and the highest saturation magnetization of 52.23 emu/g. All the NMCCFx nanoferrites exhibit a microwave frequency range of 9.47–11.55 GHz, suggesting potential applications in longitudinal recording media and microwave absorbance. Moreover, the nanoferrite Ni 0.5 Mn 0.25 Co 0.25 Ce 0.1 Fe 1.9 O 4 demonstrates the highest dielectric value of 1871, with an enhancing ratio of 754 %, excellent conductivity at 3.12 μ(Ω.m)−1 along with a remarkably enhanced percentage of 369 %. Additionally, it shows a loss factor of 2.17, with a notable improvement percentage of 26 % compared to the pure NMCCF0 sample at 50 Hz and room temperature. The elastic moduli (longitudinal, shear, Young, and bulk) of the Ni 0.5 Mn 0.25 Co 0.25 Ce 0.1 Fe 1.9 O 4 nanoferrite increased from 1.21 to 2.77 GPa, 0.25–0.76 GPa, 0.68–1.99 GPa, and 0.87–1.75 GPa, respectively. This study introduces a novel approach to Ni–Mn–Co–Ce spinel nanoferrites, highlighting their magnetic, electrical, and mechanical characteristics, which hold promise for electronic and high-frequency device applications. [ABSTRACT FROM AUTHOR]

Dinuclear Ni(II)/Ce(III) complexes, namely [Ni(o-van-dap)Ce(H2O)(NO3)3] (1) and [Ni(H2O)2(o-van-dmdap)Ce(NO3)3] (2), were synthesized and chemically and spectroscopically characterized. Single crystal X-ray analyses revealed that in both 1 and 2 bicompartmental Schiff base-type ligands (o-van-dap)2− and (o-van-dmdap)2− are present, with neighbouring cis-N2O2 and O4 donor sets. The smaller N2O2 cavity is occupied by the Ni(II) ions while the larger O4 cavity contains a Ce(III) ion; both metal ions are linked via a pair of monoatomic O-bridges with the O atoms provided by deprotonated hydroxyl groups. In complex 1 the bridging unit within the Schiff base-type ligand is formed from two carbon atoms; consequently the central Ni(II) atom has a square-planar geometry, and is thus diamagnetic. In complex 2 the bridging unit within the structure of the ligand is composed of three carbon atoms yielding a larger cavity accommodating a paramagnetic, hexacoordinated Ni(II) atom, whose coordination sphere is completed by two axial aqua ligands. The Ce(III) atoms in both 1 and 2 are additionally coordinated by three chelating nitrato co-ligands resulting in coordination number 10 in 2, while another aqua ligand increases the coordination number of the Ce(III) atom in 1 to 11. Variable temperature dc magnetic studies of both 1 and 2 (2–300 K) corroborate the diamagnetism of the Ni(II) atom (S = 0) in 1 and paramagnetism of the Ni(II) atom (S = 1) in 2. The ac magnetic studies showed that both complexes 1 and 2 exhibit field induced slow magnetic relaxation. The obtained values of the energy barriers are Δ/kB = 24.1 K with τ0 = 6.96 × 10−8 s for 1, and Δ/kB = 9.88 K with τ0 = 5.36 × 10−7 s for 2. One-atomic elongation of the bridging unit in the bicompartmental ligand induces change of the magnetic character of the Ni(II) central atoms from S = 0 in 1 to S = 1 in 2, and this change leads to significant differences in the values of the respective Δ/kB parameters. Theoretical ab initio calculations for complexes 1 and 2 were performed to investigate their magnetic properties in detail. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis of six novel triazole-based heteroscorpionate ligands based on heterocycle metathesis reactions and their iron(II) complexes. Single crystal structure analyses were performed, the spectroscopic and magnetic properties of the obtained complexes were studied and their spin crossover–structural relationships were compared to those obtained for their pyrazole-based analogues reported in the literature. In particular, the amino derivative complex bis[hydrobis(pyrazol-1-yl)(3-amino-1,2,4-triazol-1-yl)]iron(II) obtained by post-synthetic catalytic nitro-group reduction under pressure of hydrogen in an autoclave presents a scarce gradual spin crossover behavior at room temperature. The profile of the SCO curve can be explained by the presence of only relatively weak H bonds, spreading only in one dimension. Among the interesting spin transition behaviors observed for the different complexes, such stable, complete and gradual spin crossover at room temperature makes this neutral complex a good candidate for sublimation and future investigation as an active element notably for thermoreflectance-based surface microthermometry applications. [ABSTRACT FROM AUTHOR]

The synthesis, structures, adsorption, and magnetic properties of two two-dimensional (2D) coordination polymers, [M(btca)1/2(bpe)1/2(H2O)2]n (M = Ni2+ (1) and Co2+ (2); H4btca = 1,2,4,5-benzenetetracarboxylic acid; bpe = 1,2-di(4-pyridyl)ethane) constructed by mixed bipyridyl–tetracarboxylate ligands were reported. Single-crystal X-ray diffraction studies reveal the 3D hydrogen-bonded networks sustained by O–H⋯O H bonds between the 2D layers. The 2D structure topology of the compounds is a new {4.6·2}2{4·2.6·2.8·2} bex topology while the 3D framework is different because of the distinct H bond interactions. Both compounds exhibit high thermal stability above 150 °C. N2 adsorption measurements reveal that both compounds are non-porous structures, while compound 1 exhibits CO2 adsorption, possibly due to structural expansion after CO2 accommodation. Magnetic investigations indicated that framework 2 exhibits field-induced slow magnetic relaxation due to the large magnetic anisotropy of Co2+ ions (zero-field splitting parameter D = 42.1 cm−1), while framework 1 shows simple paramagnetism with a small D of −11.3 cm−1. This work not only provides two new coordination polymers but also a potential bipyridyl–tetracarboxylate approach for the design and construction of single-ion magnet (SIM) frameworks. [ABSTRACT FROM AUTHOR]

In this study, a feasible strategy, named hydrogen mineral phase transformation (HMPT) technology, is proposed and employed to achieve efficient and clean recovery of Hainan Shilu refractory iron ore (HSRIO). The influences of HMPT roasting temperature, roasting time, and H 2 concentration on the separation index of HSRIO are investigated. Under the optimal experimental conditions, the iron concentrate grade increases from 62.5% to 67.9%, and the iron recovery increases from 65.0% to 94.7% compared with the original beneficiation process. In addition, the evolution of mineral phases, magnetic properties, and mineral microstructures is analyzed using XRD, VSM, SEM, and high-temperature hot-stage microscopy. It is revealed that the transformation of hematite to magnetite occurs during the HMPT process, with the newly formed magnetite exhibiting a loose and porous reticulation structure. This study is of guiding significance for the development of Hainan Shilu refractory iron ore with high efficiency and zero-carbon emission. [Display omitted] • Efficient recovery of HSRIO achieved through environmentally friendly HMPT technology. • Precise phase control enhances mineral magnetism, thereby promoting iron ore recovery. • The reduction reaction of the mineral proceeds from the surface inward. • This study provides theoretical support for the industrial production of HMPT. [ABSTRACT FROM AUTHOR]

Chemoselective reduction of nitroarenes to corresponding arylamines is a significant reaction in the chemical industry. However, in the presence of other reducible groups, including halogenated nitrobenzene, nitrobiphenyl, and nitroquinoline in the same molecule of nitroaromatics, the control of chemoselectivity remains challenging. Here, a facile fabrication of a heterogeneous iron‐based catalyst is reported as a potential alternative to precious metal catalysts for the chemoselective reduction of nitroarenes. The pyrolysis of iron acetate/polyacrylonitrile (PAN) template under an inert atmosphere furnishes active Fe3O4 nanoparticles (NPs) encapsulated in nitrogen‐doped (N‐doped) carbon layers, which can provide more catalytic active sites (Fe3O4/PAN@800). Notably, non‐precious iron oxide NPs supported on N‐doped carbon support prevent aggregation, thereby enhancing the catalytic activity. The sustainable and reusable Fe3O4/PAN@800 catalyst, having only 0.8% metal content as demonstrated by x‐ray photoelectron spectroscopy, delivers excellent yields of corresponding amines from differently functionalized nitroarenes. Hydrogenation of a series of structurally functionalized nitroarenes produced excellent yields of anilines, which serve as building blocks and intermediates for fine and bulk chemicals. Hydrogenation of 2‐chloro‐3‐nitropyridine, 2‐nitro‐1,1′‐biphenyl, ortho‐nitroaniline, and 4‐aminophenyl acrylonitrile yielded respective anilines up to 99%. The active sites of Fe3O4 have magnetic performance, hence, the catalyst can be easily recovered using a magnet and reused for at least five cycles without significant loss of catalytic activity. Therefore, the easily prepared, cost‐effective, and reusable Fe3O4/PAN@800 catalyst presented in this study shows potential for applications in the selective reduction of aromatic nitro compounds. Consequently, this study potentially establishes a guideline for the facile preparation of abundant transition‐non‐noble metal‐based reusable supported catalysts for various applications in the chemical industry. [ABSTRACT FROM AUTHOR]

The configurations, electronic, and magnetic properties of the H2DBP-M clusters have been investigated via density functional theory. The results reveal that the TM atoms for the H2DBP-M (M = Sc , Y, Zr, Nb, Lu, and Hf) clusters deviate from the center planes of the clusters. The H2DBP-M (M = Sc , Y, and Lu) clusters display the largest dipole magnitudes. Based on the binding energy per atom and HOMO-LUMO gap, the H2DBP-Ni and H2DBP-Lu clusters are the most favorable for synthesis. The charge transfer amounts of the TM (TM = Sc , Zn, Y, Cd, Hf, and Hg) atoms for the H2DBP-M clusters are larger. The TM-d orbitals of the H2DBP-M (M = Ti ∼ Co and Cu) clusters contribute significantly to the Fermi levels. The spin densities of the TM atoms for the H2DBP-M clusters reduce to 0 except for that (V = 2. 4 5 9 | e |) of the H2DBP-V clusters. [ABSTRACT FROM AUTHOR]

In the present study, SrTiO3 was selected to enhance the multiferroic characteristics of Bi0.88Sm0.12FeO3 (BSF) ceramics. With increasing SrTiO3 content, the principal phase of BSF ceramic transitions from rhombohedral R3c to Pna21. Through DSC and dielectric analysis, it was observed that both the Curie temperature and Néel temperature decreased proportionally with the augmentation of SrTiO3 content. When x =.1, the optimal ferroelectric performance is achieved, and the highest remanent polarization value is 55.47 µC/cm2, significantly surpassing that of BSF ceramics. Moreover, the PFM test results showed that as the substitution content increased, the domains in the BSF ceramic gradually transformed from normal ferroelectric domains to polar nanomicro‐domains. Magnetic and magnetoelectric results show that when x =.1, the best magnetic properties are obtained, Mr = 59.7 emu/mol. The magnetoelectric coefficient αME initially increased and then decreased with the increasing SrTiO3 content, reaching its optimum magnetoelectric properties at x =.1, where αME =.47 mV cm–1 Oe–1. In summary, when the substitution amount of SrTiO3 reaches 10%, the ferroelectric, magnetic, and magnetoelectric properties of BSF ceramics are significantly improved. [ABSTRACT FROM AUTHOR]

This study presents an easy method for synthesizing ultrafine NixFe1–xFe2O4 nanoparticles with adjustable composition (x = 0–.8), followed by their stabilization into ferrofluids. Structural identification of the crystalline structure, lattice points, and grain boundaries from the broadened diffraction peaks reveal an average crystalline size of the nanoparticles as 10–16.5 nm. Transmission electron microscopy images reveal spherical magnetite nanoparticles with a particle size ranging from 6 to 13 nm, consistent with diffraction studies. In ferrofluids, the NixFe1–xFe2O4 nanoparticles are stabilized in kerosene with oleic acid, a surfactant. Absorbance data of the ferrofluids is seen in the 200–400 nm wavelength region of UV–vis spectra. The magnetic properties of the samples are probed using a Superconducting Quantum Interference Device. The synthesized samples exhibit superparamagnetic behavior at room temperature (300 K). The saturation magnetization of the samples decreases with an increase in Ni composition (x = 0–.8), ranging from 54 to 28 emu/g. This study explores the magnetic and magneto‐optical properties of NixFe1–xFe2O4 ferrofluids. Magneto‐viscosity of ferrofluids is also studied, and the final application of such ferrofluids in data storage, catalysis, and biomedical applications is discussed. [ABSTRACT FROM AUTHOR]

Crystalline Sm3+ substituted V-type hexaferrites Sr 1-x Sm x Fe 8 SnO 15 with composition (x = 0.00, 0.02, 0.06, 0.10) were synthesized using hydrothermal method. With the substitution of Sm3+ ions, the lattice constant 'c' experienced a decrement from 54.4600 Å to 53.0200 Å while the value of lattice constant 'a' firstly increased and then decreased. The crystallite size varied from 37.95 to 50.86 nm. The spherical shape of particles was analyzed by Atomic Force Microscopy (AFM). The VSM analysis revealed that the samples inherent the soft magnetic properties as evidenced by the coercivity value being below 1 k Oe which exemplifies its usefulness in the field of microwave absorption properties. The successive production of heat during hyperthermia analysis indicated the use of this material in cancer cell treatment. The UV visible spectroscopy technique was utilized to investigate many parameter including absorption, Urbach-energy, and band gap. It can be affirmed that the prepared material might be useful for photo-catalytic purposes and hyperthermia applications. [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 investigates Co 40 Fe 40 Dy 20 thin films on glass substrates with thicknesses ranging from 10 nm to 50 nm under four conditions: as-deposited, annealed at 100 °C, 200 °C, and 300 °C. X-ray diffraction (XRD) confirms film amorphousness due to limited thermal energy. Maximum low-frequency alternate-current magnetic susceptibility (χ ac) is observed at thicker films and higher annealing temperatures, with films at 300 °C showing the highest value 0.41. Annealing at 200 °C yields exceptional properties high saturation magnetization (M s) 748 emu/cm³ and low coercivity (Hc) 10 Oe, though Ms decreases at 300 °C due to thermal effects. Electrical resistivity and sheet resistance decrease with thickness and annealing, enhancing carrier transport. Transmittance (%) decreases notably with increased thickness, attributed to thickness and interface effects. Variations in surface roughness from annealing affect properties, with smoother surfaces improving carrier conductivity but reducing optical transparency. Overall, Co 40 Fe 40 Dy 20 exhibits excellent soft magnetic properties suitable for various applications. [ABSTRACT FROM AUTHOR]

In this study, activated and magnetic biochar prepared from Ziziphus Jujube Seeds (ZJS) is used to remove Hexavalent Chromium (Cr(VI)) using Fixed Bed Column Experiment. Physicochemical characteristics of the activated and magnetic biochar such as functional groups, surface area, morphological study, and magnetic properties were analyzed. The column experiment was carried out for varying bed heights (2, 4, 6, 8, 10 cm), flow rates (20, 30 ml/min), and initial chromium concentrations (40, 60, 80 ppm) to determine adsorption performance of the studied biochar. The characteristic study found that magnetic biochar (MB) has good magnetic properties and crystallinity nature with essential functional groups such as C-O, FeO. The study found that Magnetic Biochar (MB) effectively removed 99% of hexavalent chromium through column adsorption under optimal conditions, including bed height of 6 cm, 60ppm Chromium concentration, and flow rate of 20 ml/min. Kinetic model study showed that Magnetic Biochar (MB) showed very good agreement with Adam Bohart Model, with R2 of 0.97, which is best fit model than other model studies whereas the other model showed a lesser R2 value. The study reveals that magnetic biochar from Ziziphus Jujube Seed is optimal adsorbent for removal of Cr(VI) through column adsorption experiment. RESEARCH HIGHLIGHTS: Activated, Magnetic biochar and Magnetic activated biochar was used to remove Cr(VI) in fixed bed column studies. Maximum Cr(VI) removal efficiency was achieved at 6 cm bed height and 20 ml/min for all biochars. Magnetic biochar showed maximum Cr(VI) removal efficiency of 99% at 60 ppm and 95% at 40 and 80 ppm. Langmuir isotherm, Pseudo second order kinetic and Adam Bohart Model were the best fit kinetic model. [ABSTRACT FROM AUTHOR]

[Display omitted] Binary superparticles formed by self-assembling two different types of nanoparticles may utilize the synergistic interactions and create advanced multifunctional materials. Bi-magnetic superparticles with a core–shell structure have unique properties due to their specific spatial configurations. Herein, we built Mn 3 O 4 @Ni core–shell binary superparticles via an emulsion self-assembly technique. The superparticles are generated with a spherical morphology, and have a typical average size of about 240 nm. By altering the ratio of the two magnetic nanoparticles, the thickness of Ni shells can be adjusted. Oleic acid ligands are crucial for the formation of core–shell structure. Magnetic analysis suggests that core–shell superparticles display dual-phase magnetic interactions, contrasting with the single-phase magnetic behaviors of commonly core–shell magnetic nanoparticles. The calculation on the effective magnetic anisotropy constants indicates that the presence of Ni shell layers reduces the dipole interactions among the Mn 3 O 4 core particles. Due to the presence of Ni nanoparticle shells, the blocking temperature of Mn 3 O 4 is reduced, while the Curie temperature of Mn 3 O 4 is independent on Ni content. Tunable magnetic properties can be achieved by modulating the Ni nanoparticle shell thickness. This study offers insights for the development of core–shell superparticles with varied magnetic characteristics. [ABSTRACT FROM AUTHOR]

The magnetic properties of Ho6MnBi2 and Ho6FeBi2 crystals are investigated by means of density functional theory. These materials are currently an active subject of research in the context of magnetic refrigeration applications since they exhibit a remarkable magnetocaloric effect. In this work, the equation of state, density of states and magnetic moments are calculated and compared with previous experimental results for these materials. Also, the Curie temperatures for the paramagnetic to ferromagnetic phase transition observed in these systems are calculated from first principles. All the calculated quantities are in reasonable agreement with experimental data, which suggests that density functional theory could provide a reliable framework to theoretically investigate the magnetic properties of intermetallic ternary compounds. [ABSTRACT FROM AUTHOR]

Two series of europium-doped zinc borotellurite glass embedded with nickel oxide nanoparticles (NiO NPs) in the composition (60-x) TeO2-30B2O3-10ZnO-xEu2O3 (x = 0.5, 1,1.5, 2, 2.5 mol%) and (58-x) TeO2-30B2O3-10ZnO-2Eu2O3-xNiO (x = 0.5, 1, 1.5, 2, 2.5 mol%) are prepared using conventional melt-quenching technique. The amorphous nature of the prepared glasses is confirmed with the aid of the X-ray diffraction technique. Transmission electron microscopy investigations confirmed the presence of spherical and non-spherical NiO NPs with an average size of around 4.6 nm distributed and growing uniformly in the glassy matrix. The lattice spacing was inferred from high-resolution transmission electron microscopy, the estimated distance between the crystal lattice spacing being about 0.198 nm, representing the NiO NPs' fingerprint identification. The elemental weight fractions of the samples were confirmed by energy dispersive X-ray analysis and these results geared to the determination of adequate atomic number and photon energy response of the samples. The UV–Vis-NIR absorption spectra show seven bands corresponding to transition bands from ground states 7F0 and 7F1 to excited states 7F1 → 5G2, 7F1 → 5D3, 7F0 → 5D2, 7F0 → 5D1, 7F1 → 5D1, 7F0 → 7F6 and 7F1 → 7F6. The infrared to visible frequency down-conversion emission under 395 nm excitation shows six emission bands centered at 519.77 nm, 539.44 nm, 574 nm, 600.25 nm, 634.4 nm, and 683.69 nm, these peaks' positions are related to the transitions 5D1 → 7F0, 5D1 → 7F1, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4, respectively. The bonding parameter (δ) exhibits a positive sign for all TBZE glass samples, showing that the Eu3+ ligand possesses covalent bonding characteristics. The magnetic properties of TBZEN glass were interpreted using VSM, the highest Ms content was obtained when 2 mol% of NiO NP content was embedded in the glass composite and the highest Mr content was obtained for 1.5 mol% of NiO NPs. The maximum possible magnetization ratio Mr/Ms 2.77 was achieved for the glass sample with 1.5 mol% NiO NPs. These findings reveal that the europium-doped zinc borotellurite glass embedded with NiO NPs can be a promising candidate for storage device application. [ABSTRACT FROM AUTHOR]

β-Gallium oxide has well-studied electrical characteristics but relatively less explored optical as well as magnetic properties. In this work, pure and Ni-doped β-Ga2O3 polycrystalline powders were prepared using a hydrothermal method to study the structural, optical, and magnetic properties at various concentrations of Ni at 1 M%, 3 M%, 5 M%, and 7 M%. XRD analysis confirmed the formation of monoclinic β-Ga2O3 up to Ni 1 M% doping. The formation of additional peaks was observed exclusively for the samples doped with Ni from 3 M% to 7 M%. These additional peaks belong to NiGa2O4 that has an inverse spinel structure. The reflectance studies using UV–Vis diffuse reflectance spectroscopy shows a reduction in bandgap from approximately 4.7 eV to 4.1 eV with the addition of the dopant. The emission peaks observed from photoluminescence studies shows UV, blue, and green emissions with varying intensity. Room-temperature magnetic studies performed using a vibrating sample magnetometer showed a transition from the diamagnetic state of the pure sample to the antiferromagnetic state with increasing Ni concentration in the doped samples. The diamagnetic properties of β-Ga2O3 makes it ineffective in spintronic applications. From the present work, the improved magnetism due to Ni doping coupled with the optical properties suggests that nickel-doped gallium oxide can be used as an optical magnetic bifunctional material. [ABSTRACT FROM AUTHOR]

Defects and defective technology are considered to be an efficient method for improving electromagnetic wave (EMW) absorption performance. In this study, W-type barium hexaferrite BaCo2Fe16O27 (BCFO) composites with Sm doping were synthesized by a simple ball milling and subsequent annealing process. The phase structure characteristics, magnetic properties, and microwave absorption performance of the BCFO composites were systematically investigated. Specifically, Sm-doped and annealed BCFO composites demonstrated outstanding microwave absorption characteristics because of the efficient interaction between ideal impedance matching and large dielectric loss, specifically, a minimum reflection loss (RL) value of −28.57 dB at 8.5 GHz with 3 mm thickness. Moreover, a broad effective absorption bandwidth reaches 11 GHz, covering the range of 7–18 GHz. It is believed that defects and vacancies induced by Sm doping or annealing in the Ar atmosphere may be an effective means for enhancing microwave absorption, and related mechanisms are discussed in detail. [ABSTRACT FROM AUTHOR]

New cobalt(II)‐based complexes with [N2O2] coordination formed by two bis‐chelate ligands were synthesized and characterized by a multi‐technique approach. The complexes possess an easy‐axis anisotropy (D<0) and magnetic measurements show a field‐induced slow relaxation of magnetization. The spin‐reversal barriers, i. e., the splitting of the two lowest Kramers doublets (UZFS), have been measured by THz‐EPR spectroscopy, which allows to distinguish the two crystallographically independent species present in one of the complexes. Based on these experimental UZFS energies together with those for related complexes reported in literature, it was possible to establish magneto‐structural correlations. UZFS linearly depends on the elongation parameter ϵT of the (pseudo‐)tetrahedral coordination, which is given by the ratio between the average obtuse and acute angles at the cobalt(II) ion, while UZFS was found to be virtually independent of the twist angle of the chelate planes. With increasing deviation from the orthogonality of the latter, the rhombicity (|E/D|) increases. [ABSTRACT FROM AUTHOR]

Conventionally, octahedral (Oh) coordination symmetry of lanthanide centers is not ideal for constructing high-performance single-molecule magnets (SMMs). However, introducing a strong ligand field in the axial direction to increase crystal field splitting can potentially overcome this limitation. Herein, we successfully obtained two dysprosium(III) single-molecule magnets, [Dy(OCtBu3)X2(py)3] (X = Cl (1), I (2), py = pyridine), in Oh coordination symmetry. The two complexes differ only in the coordinating anions on the equatorial plane, yet their magnetic performances are distinctly different. When chloride is replaced by a weaker donor iodide, the energy barrier is dramatically improved from 29 cm−1 (1) to 860 cm−1 (2), highlighting the importance of weakening the transverse ligand field and maximizing the axial ligand field for high-performance SMMs. [ABSTRACT FROM AUTHOR]

Organometallic dysprosocenium-based molecular magnets are the forefront runners in offering giant magnetic anisotropy and blocking temperatures close to the boiling point of liquid nitrogen. Attaining linearity in the organometallic dysprosocenium complexes is the key to generating giant magnetic anisotropy and blocking barriers. In the present study, we have unravelled the coordination ability of the substituted fullerene (C55X5)− (where X = CCH3, B, and N) generated by fencing around the five-membered ring of fullerene towards stabilizing a new family of exohedral dysprosium organometallic complexes showcasing giant magnetic anisotropy and blockade barriers. Eight exohedral mononuclear dysprosium organometallic complexes, namely [Dy(η5-C55X5)(η4-C4H4)] (1), [Dy(η5-C55X5)(η5-Cp)]+ (2), [Dy(η5-C55X5)(η5-Cp*)]+ (3), [Dy(η5-C55X5)(η6-C6H6)]2+ (4), [Dy(η5-C55X5)(η8-C8H8)] (5), [Dy(η5-C55X5)2]+ (6) (where X = CCH3), [Dy(η5-C55B5)2]+ (7) and [Dy(η5-C55N5)2]+ (8), were studied using scalar relativistic density functional theory (SR-DFT) and the complete active space self-consistent field (CASSCF) methodology to shed light on the structure, stability, bonding and single-ion magnetic properties. SR-DFT calculations predict complexes 1–8 to be highly stable, with a strictly linear geometry around the Dy(III) ion in complexes 6–8. Energy Decomposition Analysis (EDA) predicts the following order for interaction energy (ΔEint value): 5 > 1 > 2 ≈ 3 > 6 > 7 > 8 > 4, with sizable 4f-ligand covalency in all the complexes. CASSCF calculations on complexes 1–8 predict stabilization of mJ ‖±15/2〉 as the ground state for all the complexes except for 5, with the following trend in the Ucal values: 6 (1573 cm−1) ≈ 3 (1569 cm−1) > 1 (1538 cm−1) > 8 (1347 cm−1) > 2 (1305 cm−1) > 7 (1284 cm−1) > 4 (1125 cm−1) > 5 (108 cm−1). Ab initio ligand field theory (AILFT) analysis provides a rationale for Ucal ordering, where π-type 4f-ligand interactions in complexes 1–4 and 6–8 offer giant barrier height while the large (C8H8)2− rings generate δ-type interaction in 5, which diminishes the axiality in the ligand field. Our detailed finding suggests that the exohedral organometallic dysprosocenium complexes are more linear compared to bent [DyCp*2]+ cations and display a giant barrier height exceeding 1500 cm−1 with negligible quantum tunnelling of magnetization (QTM) – a new approach to design highly anisotropic dysprosium organometallic complexes. [ABSTRACT FROM AUTHOR]

Multifunctional magnetic materials have broad application prospects in molecular switches and information storage. In this study, four mononuclear Fe(II) complexes are synthesized using a series of pyrenylhydrazone ligands HL1–4. Two deprotonated ligands are coordinated to the iron(II) ions in an enolic form, leading to neutral complexes FeII(Lx)2·xsol with a FeIIN4O2 octahedral coordination environment. Magnetic measurements suggest that complex Fe(L1)2·2ACE (1·2ACE, ACE = acetone) is mainly low spin below 300 K and complex Fe(L3)2·ACE (3·ACE) is high spin, whereas complexes Fe(L2)2 (2) and Fe(L4)2·6H2O (4·6H2O) exhibit gradual spin crossover behavior. The spin states of complexes 1–4 are confirmed by single-crystal X-ray diffraction analysis. The substituent effect on the magnetic properties of the complexes is significant in this system. Temperature-dependent fluorescence emission spectra show the coexistence but no coupling effect of spin crossover and fluorescence for complexes 2 and 4·6H2O. [ABSTRACT FROM AUTHOR]

In this work, we applied Monte Carlo simulations under the Metropolis algorithm to study the magnetic and magneto-caloric properties of the fullerene C 3 6 system formed with mixed spins: 2 and 5/2. We inspected the effects of not only the crystal magnetic field but also the external magnetic field and the coupling interaction between spins. In the first part, we illustrated the ground state phase diagrams in the planes of the external magnetic field, the coupling interaction between spins and the crystal magnetic field. Also, we have established these phase diagrams for null temperature. It is found that not only the total magnetizations predict the blocking temperature value t B = 5. 5 1 1 7 , but also the magnetic susceptibilities confirm this value. The effects of varying temperature values when fixing the other physical parameters have been outlined. In particular, the studied system showed a shifting between the phases the ferromagnetic phase and the paramagnetic one, at very low temperature values. [ABSTRACT FROM AUTHOR]

In this study, the WIEN2k code, utilizing the full potential linearized augmented plane wave (FPLAPW) approach within the framework of density functional theory (DFT), explicitly employing the PBEsol approximation, is employed to investigate the fundamental properties of W-doped and (Mo, W) co-doped cubic CeO2. Herein, lattice constants, bulk modulus and cell volumes were evaluated for structural properties. The total density of states (TDOS) for various doped and co-doped CeO2 systems was used to explain the origin of magnetic behavior. The band structure (BS) calculations show that the doped and co-doped materials exhibit semiconductor behavior with a direct bandgap in both spin channels. The calculated total spin magnetic moments of W/CeO2 and (Mo, W)/CeO2 alloys are 2.002 μ B and 4.007 μ B , respectively. Furthermore, the optical absorption shows absorption peaks in the visible range and a redshift. As a result, adding molybdenum and tungsten additives improves the electro-optical properties of previous materials. [ABSTRACT FROM AUTHOR]