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The search for spin-reorientation (SR) phase transitions, a spontaneous rotation of ordered magnetic moments, in ferrimagnetic (FiM) materials, which carry a net magnetization, is of fundamental and practical interest for applications in the field of spintronics. In this work, we have investigated Mn self-doped (Er 0.7 Mn 0.3)MnO 3 solid solution with GdFeO 3 -type Pnma perovskite structure by combining specific heat, magnetic susceptibility and neutron powder diffraction measurements. We provide experimental evidence for FiM order below T C = 104 K, and a spontaneous SR transition at T SR = 11 K. A FiM structure appears in all (R 1-x Mn x)MnO 3 compounds with R = Dy–Lu for x ≥ 0.2. But in this structural family, R = Er is the only material with a SR transition. FiM order in (Er 0.7 Mn 0.3)MnO 3 appears with ferromagnetic (FM) ordering of Mn3+ and Mn4+ cations at the B site along the a -direction, which are antiferromagnetically (AFM) coupled with Er3+ and Mn2+ cations at the A site. At T SR , ordered Er3+ change direction from the magnetically harder a -axis to the magnetically easy b -axis and induce a change of the whole FiM structure, including the direction of all Mn spins from the irreducible representation m GM3+ to m GM4+. We calculated the crystal-field (CF) anisotropy for Ho3+ in (Ho 0.8 Mn 0.2)MnO 3 and Er3+ in (Er 0.7 Mn 0.3)MnO 3 , based on the point charge model; the results revealed large magnetic anisotropies. For the FiM structure of (Ho 0.8 Mn 0.2)MnO 3 , the magnetically easy a -axis of Ho3+ keeps the high-temperature magnetic directions along the a -axis and gives rise to a pronounced magnetization reversal effect at low temperature because of a significant rise of Ho3+ ordered moments. On the other hand, for the FiM structure of (Er 0.7 Mn 0.3)MnO 3 , the magnetically easy b -axis of Er3+ gives rise to a SR phase transition at T SR , which does not lead to magnetization reversal even though Er3+ ordered moments rise significantly at low temperatures. [ABSTRACT FROM AUTHOR]

The reaction of MnCl2·4H2O with HL ((1-methyl-1H-imidazol-2-yl)methanol) and pdH2 (1, 3 propanediol) in a basic MeCN solution results in the formation of a mixed-valence [Mn20] cationic cluster and two [MnIICl4] counter anions. The metallic skeleton of the cluster describes two geometrically equivalent mixed-valent, linked [MnIII6MnII4] supertetrahedra in which nearest-neighbor metal ions have a different oxidation state. Magnetic susceptibility, magnetization data and heat capacity measurements support evidence of predominant ferromagnetic correlations, leading to a s = 22 spin ground state for the [MnIII6MnII4] supertetrahedra, which are pair-linked by a weak antiferromagnetic coupling. The properties are discussed in the context of the magnetocaloric effect and the potential application of this compound in cryogenic refrigeration. [ABSTRACT FROM AUTHOR]

The low field magnetic susceptibility (χLF) measured in the 1116‐m‐long Dévaványa core (Pannonian Basin) is a quasi‐continuous record of the Plio–Pleistocene Mid‐European mountain permafrost development. The continuity of fluvial conditions is confirmed by seismic data, and the detrital origin of magnetite is indicated by frequency‐dependent susceptibility measurements, scanning electron microscope, and hysteresis investigations. The χLF record is correlated to the δ18O curve (LR04) supported by palaeomagnetic data. The colour of samples documents precession and obliquity cycles in local facies variations, but the χLF indicates the dominance of 100‐ka eccentricity cycles in the linked mountainous permafrost events. Comparison with orbital solutions revealed that the long‐term development of permafrost occurs as a result of amplitude modulation of the 100‐ka eccentricity cycles. Increases in amplitude of the 100‐ka cycles inhibits permafrost development due to shortened winters. Thus, if extremes are present, the permafrost regions are limited or disappear, but if the 100‐ka eccentricity cycles are attenuated, permanent frost can extend into the temperate zone. This amplitude modulation may also be responsible for the early glaciations during the Pliocene, for the intensification of Northern Hemisphere glaciation, foreshadows cooling in the forthcoming 405‐ka term, and allows the change from 41‐ka cycles to 100‐ka ones in the Mid‐Pleistocene Transition to be explained. The 41‐ka cycles are the result of obliquity‐controlled changes close to the polar cycles, while 100‐ka cycles occur when the amplitude attenuation of the 100‐ka eccentricity cycles enables extended glaciations that suppress the regular 41‐ka cycles. Higher mountains in the catchments enable higher resolution of permafrost records documenting even smaller glaciations. However, the similarities in the overall trends in χLF records of catchment areas with 1500‐m difference in their altitude is a potential counter‐argument when considering the role of tectonic elevations in the expansions of mountainous permafrost. [ABSTRACT FROM AUTHOR]

Over the Nullarbor Plain in South Australia, the Desert Fireball Network detected a fireball on the night of June 1, 2019 (7:30 pm local time), and 6 weeks later recovered a single meteorite (42 g) named Arpu Kuilpu. This meteorite was then distributed to a consortium of collaborating institutions to be measured and analyzed by a number of methodologies including SEM‐EDS, EPMA, ICP‐MS, gamma‐ray spectrometry, ideal gas pycnometry, magnetic susceptibility measurement, μCT, optical microscopy, and accelerator and noble gas mass spectrometry techniques. These analyses revealed that Arpu Kuilpu is an unbrecciated H5 ordinary chondrite, with minimal weathering (W0‐1) and minimal shock (S2). The olivine and pyroxene mineral compositions (in mole%) are Fa: 19.2 ± 0.2 and Fs: 16.8 ± 0.2, further supporting the H5 type and class. The measured oxygen isotopes are also consistent with an H chondrite (δ17O‰ = 2.904 ± 0.177; δ18O‰ = 4.163 ± 0.336; Δ17O‰ = 0.740 ± 0.002). Ideal gas pycnometry measured bulk and grain densities of 3.66 ± 0.02 and 3.77 ± 0.02 g cm−3, respectively, yielding a porosity of 3.0% ± 0.7. The magnetic susceptibility of this meteorite is log χ = 5.16 ± 0.08. The most recent impact‐related heating event experienced by Arpu Kuilpu was measured by 40Ar/39Ar chronology to be 4467 ± 16 Ma, while the cosmic ray exposure age is estimated to be between 6 and 8 Ma. The noble gas isotopes, radionuclides, and fireball observations all indicate that Arpu Kuilpu's meteoroid was quite small (maximum radius of 10 cm, though more likely between 1 and 5 cm). Although this meteorite is a rather ordinary ordinary chondrite, its prior orbit resembled that of a Jupiter Family Comet (JFC) further lending support to the assertion that many cm‐ to m‐sized objects on JFC orbits are asteroidal rather than cometary in origin. [ABSTRACT FROM AUTHOR]

The introduction of the cerium(III) analogue (1‐Ce, Ln = Ce) of (tert‐butoxido)chloridopentakis(tetrahydrofuran)lanthanide(III) tetraphenylborate tetrahydrofuran disolvate, [Ln{OC(CH3)3}Cl(C4H8O)5][B(C6H5)4]·2C4H8O or [Ln(OtBu)Cl(THF)5](BPh4)·2THF (1‐Ln) has been achieved with a structural comparison between the existing solid‐state structures of other rare earth analogues and the title compound at 100 and 180 K. The cation in 1‐Ce is targeted as the cerium(III) ion possesses the criteria to exhibit slow magnetic relaxation in axial point‐charge crystal fields, akin to the dysprosium(III) ion in 1‐Dy. AC magnetic susceptibility experiments reveal no such behaviour for 1‐Ce, putting the viability of cerium‐based SMMs into question. [ABSTRACT FROM AUTHOR]

A combination of magnetic polarity and rock magnetic analysis on the well‐documented section of the Um Sohryngkew River (USR) in the south Shillong Plateau, NE India, produced a sharp reversal marking the C29r‐C29n geomagnetic polarity transition at approximately 65.688 Ma. The rock magnetic studies indicate ferrimagnetic dominant mineralogy with abundance of SSD grains, with an anomalous peak in susceptibility coinciding with Ir‐rich limonitic layer. The magnetic reversal occurs precisely 61 m above the Ir‐rich distinct in situ limonitic layer, indicating that the C29r‐C29n geomagnetic reversal post‐dates the widely accepted Ir‐anomaly based K‐Pg boundary by approximately 355 Ka. Furthermore, the rock magnetic studies indicate its frequency dependence coinciding with the Ir‐rich limonitic layer suggesting a possible dust/aerosol source, while akaganéite is reported from the interval approximately 1 m below peak susceptibility, indicating signature of Deccan volcanism. This study infers the completeness of the USR section with a high rate of sedimentation of approximately 17 cm/ka among the marine K‐Pg boundary sections in the world. [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]

This study identifies factors influencing spatial and temporal variations in magnetic susceptibility and heavy metal content in soils and airborne particulate matter within the Kyiv megapolis, Ukraine, and highlights how source apportionment differs in the long and short run. Topsoil magnetic susceptibility anomalies of > 70 × 10−8 m3kg−1 are observed around old factories. The tree bark magnetic susceptibility map provides a record of industry general low emissions for the last 2–3 decades. The patterns of both spatial distributions confirm that factory emissions dominate the composition of particulate falling on the ground in urban area, with exclusion of streets with heavy traffic. Enhanced concentrations of Cu, Ni, and Zn have been found in urban soils, showing a positive correlation with magnetic susceptibility. Re-suspended road dust dominates temporal variation of particulate matter magnetic susceptibility collected on air filters. The air at busy streets is cleaner in winter, when the street dust gets immobilized by snow cover or freezing. Industries in Kyiv pose no significant effect on air quality; the concentrations of Cr, Ni, Cu, Zn, Cd, and Pb are at normal urban level with the exception of the near vicinity to factories. Air in streets with heavy traffic is enriched with Fe and Mn. Principal component analysis reveals different pattern of air pollution for the busy streets and yard areas. Yards are less affected by road dust; thus, contribution of industrial emissions can be distinguished. The results provide context for further quantification of any alterations in ecological state of Kyiv megapolis that may have arisen from socio-economic shocks and direct threats connected to the current war. [ABSTRACT FROM AUTHOR]

The Li-ferrite and graphene oxide (GO) nanocomposites, denoted as (Li 0.5-x/2 ZnₓFe 2.5-x/2 O 4 : x = 0.25), were produced through ultrasonication. The wet method generated Li-ferrite, while the Hummers' method synthesized the GO. X-ray diffraction (XRD) was used to validate the development of Li-ferrite and GO in the nanocomposites. The dimensions of the crystal were determined between 41 and 52 nm, and the porosity of the composites increased with the higher quantity of GO. The scanning electron micrographs (SEM) of ferrites illustrated the formation of uniform and well-defined grains with consistent shapes, exhibiting properties well-suited for effective microwave absorption. The electrical resistance of spinel ferrite was measured at approximately 3.34 × 1011 Ω-cm and significantly lowered as the fraction of GO increased at ambient temperature. As per Maxwell Wagner's model, the electrical permittivity exhibited interfacial polarization with distinct real and imaginary components. The AC conductivity exhibited a positive correlation with the GO content due to the conductive properties of GO and the improved charge hopping mechanism. The frequency exponent parameter's value falls from 0.36 to 0.95 b y the Jonscher's Power law. The magnetic susceptibility of all the samples exhibited a progressive decrease as the temperature increased. The choice of using lithium-based ferrite as filler is made to strengthen the ferrite/GO composites and improve their magnetic and electrical properties. This is undertaken to harness these composites for high-frequency applications, such as their use as microwave absorbers in microwave devices. [ABSTRACT FROM AUTHOR]

The radial basis function (RBF) approximation is a rapidly developing field of mathematics. In the paper, we are concerned with the measurement of scalar physical quantities at nodes on sphere in the 3D Euclidean space and the spherical RBF interpolation of the data acquired. We employ a multiquadric as the radial basis function and the corresponding trend is a polynomial of degree 2 considered in Cartesian coordinates. Attention is paid to geodesic metrics that define the distance of two points on a sphere. The choice of a particular geodesic metric function is an important part of the construction of interpolation formula. We show the existence of an interpolation formula of the type considered. The approximation formulas of this type can be useful in the interpretation of measurements of various physical quantities. We present an example concerned with the sampling of anisotropy of magnetic susceptibility having extensive applications in geosciences and demonstrate the advantages and drawbacks of the formulas chosen, in particular the strong dependence of interpolation results on condition number of the matrix of the system considered and on round-off errors in general. [ABSTRACT FROM AUTHOR]

Background/Objectives: This systematic review and meta‐analysis aimed to investigate the role of magnetic susceptibility (χ) in deep gray matter (DGM) structures, including the putamen (PUT), globus pallidus (GP), caudate nucleus (CN), and thalamus, in the most common types of multiple sclerosis (MS) and relapsing‐remitting MS (RRMS), using quantitative susceptibility mapping (QSM). Methods: The literature was systematically reviewed up to November 2023, adhering to PRISMA guidelines. This study was conducted using a random‐effects model to calculate the standardized mean difference (SMD) in QSM values between patients with RRMS and healthy controls (HCs). Publication bias and risk of bias were also assessed. Results: Nine studies involving 1074 RRMS patients with RRMS and 640 HCs were included in the meta‐analysis. The results showed significantly higher QSM (χ) values in the PUT (SMD = 0.40, 95% confidence interval [CI] = 0.22–0.59, p =.000), GP (SMD = 0.60, 95% CI = 0.50–0.70, p =.00), and CN (SMD = 0.40, 95% CI = 0.15–0.66, p =.005) of RRMS patients compared to HCs. However, there were no significant differences in the QSM values in the thalamus between patients with RRMS and HCs (SMD = −0.33, 95% CI −0.67–0.01, p =.026). Age‐ and sex‐based subgroup analysis demonstrated that younger patients (< 40 years) in the PUT, GP, and CN groups and larger male populations (> 25%) in the PUT and GP groups had more significant χ. Interestingly, thalamic QSM values were found to decrease in RRMS patients over 40 years of age and in higher male populations. Sex‐based subgroup analysis indicated higher iron levels in the PUT and GP of RRMS patients regardless of sex. QSM values were higher in certain brain regions (PUT, GP, and CN) during the early stages (disease duration < 9.6 years) of RRMS, but lower in the thalamus during the later stages (disease duration > 9.6 years) than HCs. Discussion/Conclusion: QSM may serve as a biomarker for understanding χ value alterations such as iron dysregulation and its contribution to neurodegeneration in RRMS, especially in the basal ganglia nuclei including PUT, GP, and CN. [ABSTRACT FROM AUTHOR]

The spin crossover complex Fe(phen)2(NCS)2 and its composite, Fe(phen)2(NCS)2, combined with the conducting polymer polyaniline (PANI) plus varying concentrations of iron magnetite (Fe3O4) nanoparticles were studied. A cooperative effect is evident from the hysteresis width in the plot of magnetic susceptibility multiplied by temperature versus temperature ( χ m T versus T) for Fe(phen)2(NCS)2 with PANI plus varying concentrations of Fe3O4 nanoparticles. The hysteresis width in the composites vary no more than 2 K with respect to the pristine Fe(phen)2(NCS)2 spin crossover crystallites despite the fact that there exists a high degree of miscibility of the Fe(phen)2(NCS)2 spin crossover complex with the PANI. The Fe3O4 nanoparticles in the Fe(phen)2(NCS)2 plus PANI composite tend to agglomerate at higher concentrations regardless of the spin state of Fe(phen)2(NCS)2. Of note is that the Fe3O4 nanoparticles are shown to be antiferromagnetically coupled with the Fe(phen)2(NCS)2 when Fe(phen)2(NCS)2 is in the high spin state. [ABSTRACT FROM AUTHOR]

Mineral fabrics within igneous intrusions can archive both tectonic and magmatic processes. However, whether magmatic state fabrics reflect primary magmatic processes or regional tectonic strain is often ambiguous. To investigate when fabrics are formed, one can compare the mineral fabrics to primary magmatic features, such as the interface between solidified magmas in mingling zones. The monzodioritic Fanad pluton shows a NNE-SSW–aligned petrofabric parallel to the strike of a nearby shear zone, with dioritic enclaves aligned parallel and oblique to this petrofabric. We therefore aimed to test if the enclaves’ internal fabrics are passive and align with enclave morphology or result from progressive overprint by regional tectonic strain. Crystallographic preferred orientation and anisotropy of magnetic susceptibility data from all enclaves and the host monzodiorite revealed a NNE-SSW petrofabric parallel to the regional tectonomagmatic fabric. However, anisotropy of anhysteretic remanent magnetization data within petrofabric-oblique enclaves revealed a primary fabric parallel to the enclave long axis. Therefore, we interpret enclave morphologies to reflect earlier magmatic state deformation, with fabrics being realigned to regional tectonic deformation. These two distinct petrofabrics were interpreted in the context of the magmatic processes and the evolving late Caledonian paleostress field, with earlier magma processes distinguished from subsequent tectonic overprinting occurring in the magmatic state. Our new data show that multiple fabrics are preserved within enclaves even though all fabric development occurred within a magmatic state. Our results also show that enclaves can effectively record successive strain events, providing new insight with which to decipher tectonomagmatic processes. [ABSTRACT FROM AUTHOR]

Impurity models describe localized impurities interacting with the spins of electrons. Strong correlations lead to non-trivial behaviours of the model. In this work we present 3 different impurity models: (1) the single-impurity Kondo model; (2) the two-impurity Kondo model; (3) the two-channel Kondo model. For each model we present a spin chain emulation and utilize the density matrix renormalization group (DMRG). We study the magnetization and zero-temperature susceptibility of the impurity when a local magnetic field is applied. We get the expected relations theoretically. [ABSTRACT FROM AUTHOR]

The ternary material Mn2SiTe4 was synthesized by direct fusion using the annealing method. X-ray powder diffraction analysis indicated that this material crystallizes in the olivine-type structure, space group Pnma, Z = 4, with unit cell parameters: a = 13.905(2) Å, b = 8.128(1) Å, c = 6.526(1) Å, V = 737.6(2) Å3. This olivine structure can be described from a hexagonal close-packing of selenium atoms where manganese atoms occupy ½ of the octahedral sites while silicon atoms lay in ⅛ of the tetrahedra. The magnetic susceptibility curve indicate a possible antiferromagnetic behavior for this material. This compound is related to the ternary layered Mn3Si2Te6 recently studied as possible two-dimensional (2D) magnetic material. [ABSTRACT FROM AUTHOR]

Magnetotelluric (MT) sounding is a geophysical technique widely utilized in mineral resource surveys, where conductivity and magnetic permeability serve as essential physical parameters for forward modeling and inversion. However, the effects of conductive anisotropy and non-zero magnetic susceptibility are usually ignored. In this study, we present a three-dimensional (3D) MT modeling algorithm using Coulomb-gauged electromagnetic potentials, incorporating a mixed nodal and edge-based finite element method capable of simulating MT responses for conductive anisotropic and magnetic anomalies. Subsequently, the algorithm's accuracy was validated in two steps: first, it was compared with analytical solutions for a 1D magnetic model; then, a comparison was made with previously published numerical results for a 3D generalized conductive anisotropic model. The results of two tests show that the maximum relative error is below 0.5% for both models. Furthermore, representative models were computed to comprehensively analyze the responses of MT. The findings illustrate the relationship between anisotropic parameters and electric fields and emphasize the significance of considering the impact of magnetic susceptibility in magnetite-rich regions. [ABSTRACT FROM AUTHOR]

The marine magnetotelluric (MMT) method is a significant tool extensively utilized in offshore studies, including the understanding of the Earth's tectonics and hydrocarbon exploration. Conductive anisotropy and non-zero magnetic susceptibility are common phenomena observed in the Earth's subsurface, and MMT forward modeling is the basis of practical inversion. However, numerical modeling that incorporates both conductive anisotropy and magnetic susceptibility has received limited attention. Moreover, both accuracy and efficiency are crucial in developing a 3D MMT modeling algorithm. Therefore, we developed a multi-level parallel MMT forward modeling algorithm that is capable of simultaneously modeling conductive and magnetic arbitrary anisotropic models using the vector finite element method based on the secondary field formula. The algorithm's accuracy was validated through comparisons with previously published results for an arbitrary anisotropic model. The results show that the maximum relative error is below 2%, and the speedup reaches an impressive value of 552.41 when running with 2048 cores. Furthermore, the MMT responses of conductive anisotropy and magnetic susceptibility were comprehensively analyzed by several typical models. Our findings highlight the importance of considering magnetic susceptibility in magnetite-rich regions, particularly as the MMT responses may exhibit opposite responses for anomalies with lower resistivity and higher magnetic susceptibility compared with the surrounding rocks. [ABSTRACT FROM AUTHOR]

We performed a field induced polarization survey at Rocher du Chateau in the French Alps. This site is characterized by the presence of ophiolites with an outcrop of serpentinites. Serpentinite is characterized by high resistivity (∼0.5–10 kΩ m) and high chargeability (∼20–400 mV V−1) values. We collected two serpentinite core samples for spectral induced polarization measurements conducted in the frequency range 10 mHz–45 kHz, validating the field results. The high chargeability of serpentinite is associated with the production of magnetite during the fluid‐rock alteration, as indicated by the high magnetic susceptibility of the core samples (0.0340 SI). Using the laboratory measurements and the K‐means clustering technique, we successfully imaged the serpentinite facies and we were able to distinguish blocks of serpentinites embedded in the sedimentary cover. This approach could possibly be used for the seafloor exploration using induced polarization. Plain Language Summary: Induced polarization is a non‐invasive geophysical method known to be sensitive to the presence of semi‐conductors. Serpentinite is formed through the alteration of peridotites, resulting in the formation of magnetite, which, in addition to its magnetic properties, is responsible for a strong chargeability. The presence of an ophiolite in the French Alps provides an exceptional opportunity to study on‐shore the induced polarization response of peridotites, and especially serpentinite. The results obtained in this paper may prove to be useful for the exploration of the oceanic seafloors by documenting the properties of such materials. Key Points: The chargeability of serpentinite is high because of the presence of magnetiteTime‐domain induced polarization tomography images serpentinite in the fieldLaboratory experiments and a clustering technique help to discriminate serpentinite [ABSTRACT FROM AUTHOR]

Cyclic trinuclear homo-metal complexes, [{Fe(L3+2Br)py}3] (1) and [{Mn(L3+2Br)}3(py)2 MeOH] (2), along with a hetero-metal complex, [FeMn2(L3+2H)3(DMF)3] (3), were synthesized using asymmetric ditopic ligands (H3L3+2H: 2-(2-hydroxyphenyl)-6-ol-5-(salicylideneamino)benzoxazole, H3L3+2Br: 2-(2-hydrox-5-bromoyphenyl)-6-ol-5-(5-bromosalicylideneamino)benzoxazole). The molecular structure of 1 is characterized by a tripod structure with three-fold symmetry, where an enantiomer pair forms a dimeric capsule with dimensions of approximately 3 × 1.6 × 1.6 nm3. Complexes 2 and 3, which lack three-fold symmetry, exhibit similar molecular structures to previously reported complexes with these ligands, but do not form a capsule structure. Magnetic measurements of 1–3 reveal the presence of significantly weak antiferromagnetic interactions between the metal ions. [ABSTRACT FROM AUTHOR]

In this work, we investigate the influence of curvature on the dynamic susceptibility in FeGe nanowires, both curved and straight, hosting a skyrmionic tube texture under the action of an external bias field, using micromagnetic simulations. Our results demonstrate that both the resonance frequencies and the number of resonant peaks are highly dependent on the curvature of the system. To further understand the nature of the spin wave modes, we analyze the spatial distributions of the resonant mode amplitudes and phases, describing the differences among resonance modes observed. The ability to control the dynamic properties and frequencies of these nanostructures underscores their potential application in frequency-selective magnetic devices. [ABSTRACT FROM AUTHOR]

Elmshorn fell April 25, 2023, about 30 km northwest of the city of Hamburg (Germany). Shortly after the fall, 21 pieces were recovered totaling a mass of 4277 g. Elmshorn is a polymict and anomalous H3‐6 chondritic, fragmental breccia. The rock is a mixture of typical H chondrite lithologies and clasts of intermediate H/L (or L, based on magnetic properties) chondrite origin. In some of the 21 pieces, the H chondrite lithologies dominate, while in others the H/L (or L) chondrite components are prevalent. The H/L chondrite assignment of these components is based on the mean composition of their olivines in equilibrated type 4 fragments (~Fa21–22). The physical properties like density (3.34 g cm−3) and magnetic susceptibility (logχ <5.0, with χ in 10−9 m3 kg−1) are typical for L chondrites, which is inconsistent with the oxygen isotope compositions: all eight O isotope analyses from two different fragments clearly fall into the H chondrite field. Thus, the fragments found in the strewn field vary in mineralogy, mineral chemistry, and physical properties but not in O isotope characteristics. The sample most intensively studied belongs to the stones dominated by H chondrite lithologies. The chemical composition and nucleosynthetic Cr and Ti isotope data are typical for ordinary chondrites. The noble gases in Elmshorn represent a mixture between cosmogenic, radiogenic, and primordially trapped noble gases, while a solar wind component can be excluded. Because the chondritic rock of Elmshorn contains (a) H chondrite parent body interior materials (of types 5 and 6), (b) chondrite parent body near‐surface materials (of types 3 and 4), (c) fragments of an H/L chondrite (dominant in many stones), (d) shock‐darkened fragments, and (e) clasts of various types of impact melts but no solar wind‐implanted noble gases, the different components cannot have been part of a parent body regolith. The most straightforward explanation is that the fragmental breccia of Elmshorn represents a reaccreted rock after a catastrophic collision between an H chondrite parent body and another body with H/L (or L) chondrite characteristics but with deviating O isotope values (i.e. that of H chondrites), complete disruption of the bodies, mixing, and reassembly. This is the only straightforward way that the implantation of solar wind gases could have been avoided in this kind of complex breccia. The gas retention ages of about 2.8 Gyr possibly indicate the closure time after the catastrophic collision between H and H/L (or L) chondrite parent bodies, while the cosmic ray exposure age for Elmshorn, which had a preatmospheric radius of 25–40 cm, is ~17–20 Myr. [ABSTRACT FROM AUTHOR]

Perovskite-like compounds have attracted great attention because of their good properties, such as electrical, optical, and magnetic properties, etc. Herein, a new perovskite-like anionic dicyanamidometallate, namely (Bu3MeP)[Ni(dca)3] (1) (Bu3MeP = tributylmethylphosphine cation, dca = dicyanamide), was synthesized and structurally characterized by elemental analysis, IR spectrum, thermogravimetric analysis, and single-crystal X-ray diffraction. The compound crystallizes in the tetragonal crystal system with the chiral space group P43212, and exhibits a three-dimensional anionic dicyanamidometallate framework from Ni2+ units bridged by dicyanamides, in which tributylmethylphosphine cations are accommodated in the voids. The butyl groups present two conformations in the tributylmethylphosphine cation, resulting in chirality character occurred in compound 1. Variable-temperature magnetic susceptibility analysis indicates that weak ferromagnetic interaction exists between the nickel(II) ions coupling by µ1,5-bridings. [ABSTRACT FROM AUTHOR]

Monitoring atmospheric pollution in urban areas is challenging because pollutant deposition occurs at short distances, requiring a large amount of sampling and analysis to characterize it. Ecological indicators can help overcome this problem, allowing us to select sites with the highest deposition of pollutants from the atmosphere. Nevertheless, a major gap is the temporal characterization of the accumulation rate of magnetic particles in ecological indicators, which is critical to understand if the bioaccumulation process is linear or if saturation occurs. To overcome this problem, Parmotrema perlatum lichens were magnetically and chemically studied in a pollution gradient over space and time. Lichen transplants were exposed over 18 weeks to a high-traffic road. Results show that magnetic properties and element composition reflected both distance from the road (nonlinear decrease of up to 100 m from source) and exposure time (increasingly linearly over the entire study period with eightfold increments), showing that up to 18 weeks, the accumulation rate remained constant over time, with no saturation occurring. Chemical analysis showed a strong linear relationship between the accumulation of zinc (Zn), antimony (Sb), manganese (Mn), copper (Cu) chromium (Cr) and magnetic susceptibility. Magnetization acquisition curves reveal a time-dependent low-coercivity component, interpreted as mainly related to nonexhaust, mostly brake abrasion particle emissions. It is concluded that the magnetic properties of lichen transplants can be used in urban environments to characterize the spatial and temporal patterns of the deposition of pollution metallic particles from the atmosphere. [ABSTRACT FROM AUTHOR]

A new complex of copper(II) with methyl-5-(trifluoromethyl)pyrazol-3-yl-ketazine (H2L) was synthesized with the composition [Cu2L2]∙C2H5OH (1). Recrystallization of the sample from DMSO yielded a single crystal of the composition [Cu2L2((CH3)2SO)] (2). The coordination compounds were studied by single-crystal X-ray diffraction analysis, IR spectroscopy, and static magnetic susceptibility method. The data obtained indicate that the polydentate ligand is coordinated by both acyclic nitrogen and heterocyclic nitrogen atoms. The cytotoxic activity of the ligand and complex 1 was investigated on human cell lines MCF7 (breast adenocarcinoma), Hep2 (laryngeal carcinoma), A549 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MRC5 (non-tumor lung fibroblasts). The complex was shown to have a pronounced dose-dependent cytotoxicity towards these cell lines with LC50 values in the range of 0.18–4.03 μM. [ABSTRACT FROM AUTHOR]

Physiotherapy plays a crucial role in the rehabilitation of damaged or defective organs due to injuries or illnesses, often requiring long-term supervision by a physiotherapist in clinical settings or at home. AI-based support systems have been developed to enhance the precision and effectiveness of physiotherapy, particularly during the COVID-19 pandemic. These systems, which include game-based or tele-rehabilitation monitoring using camera-based optical systems like Vicon and Microsoft Kinect, face challenges such as privacy concerns, occlusion, and sensitivity to environmental light. Non-optical sensor alternatives, such as Inertial Movement Units (IMUs), Wi-Fi, ultrasound sensors, and ultrawide band (UWB) radar, have emerged to address these issues. Although IMUs are portable and cost-effective, they suffer from disadvantages like drift over time, limited range, and susceptibility to magnetic interference. In this study, a single UWB radar was utilized to recognize five therapeutic exercises related to the upper limb, performed by 34 male volunteers in a real environment. A novel feature fusion approach was developed to extract distinguishing features for these exercises. Various machine learning methods were applied, with the EnsembleRRGraBoost ensemble method achieving the highest recognition accuracy of 99.45%. The performance of the EnsembleRRGraBoost model was further validated using five-fold cross-validation, maintaining its high accuracy. [ABSTRACT FROM AUTHOR]

The total content, forms, and mineralogy of iron compounds in soils of forest-steppe, steppe, and semidesert zones of a large territory from the central chernozem regions to the Caspian lowland and from the Southern Urals to the Kerch Strait are studied. The study covers Chernozems (n = 40), Kastanozems (n = 15), Solonetzes (n = 7), and Calcisols (n = 7). Our results demonstrate the specific features in the distribution of total iron content, mass balance (τFe, Zr), forms of iron compounds, magnetic susceptibility (χ), and mineralogy in soil profiles. The distribution of τFe, Zr in the studied soils reflects the processes and conditions of soil formation, as well as specific lithological features. For a more comprehensive understanding of the transformation of iron compounds in steppe soils, particle-size fractions (<2, 2–5, 5–10, and 10–50 μm) have been analyzed by Mössbauer spectroscopy and magnetic susceptibility methods for Luvic Chernozem, Haplic Kastanozem, Haplic Kastanozem (Endosalic, Cambic), and Luvic Calcisol (Endosalic). In the clay fraction, a large share of Fe3+ is contained in highly dispersed oxides and hydroxides in a superparamagnetic state. In the humus-accumulative horizons of steppe soils, a decrease in the Fe2+ fraction in aluminosilicates caused by weathering is recorded. The observed correlation of the goethite/(hematite + goethite) ratio in humus-accumulative soil horizons with climatic parameters suggests the possibility to apply it for future paleoclimatic reconstructions. Mössbauer spectroscopy shows a significant increase in the content of nonsilicate iron in the humus-accumulative horizons of steppe soils as compared with the soil-forming material, which is an important confirmation for the formation of iron oxides during pedogenesis. A comparison of the methods for assaying nonsilicate iron in soils (Mössbauer spectroscopy and Mehra–Jackson extraction) demonstrates considerable differences in the results, suggesting that the chemical technique underestimates the amount of free iron forms. [ABSTRACT FROM AUTHOR]

The methods and result of scientific studies are often difficult to understand for non-specialists due to their esoteric nature. Such lack of understanding means that such work is removed from our normal life experience, and thus, the applicability, interest and use of such work can be minimal. The communication of geoscience finds a natural conduit through geoheritage. A good example of an inaccessible technique far removed from everyday experience is anisotropy of magnetic susceptibility (AMS), an extremely useful geoscience technique with many applications, including finding strain and flow directions in rocks. We explored here how to make "AMS" understandable, using three different volcanic sites where the flow of molten rock is an important aspect, each situated in different types of geoheritage visitation context (wild trekkers, beach visitors, and walkers). The method we developed and tested follows the production of simple and adapted explanations, and is coupled with geoheritage inventorying and communication. We utilized the tangible geological features of outcrops, as well as intangible elements such as rock magnetic data, and conducted a geoheritage inventory using the modified geosite assessment model (M-GAM) to create narratives for popular comprehension. The M-GAM analysis has identified the geosites of the San Bartolo lava flow of the Stromboli volcano for the communication of AMS. Later, a simple and comprehensible definition of AMS and thus of the flow processes was created using a step-by-step process. This method could be useful for scientific studies to allow them to reach out to a wider public, using their input in the simple explanation stage to con-construct a narrative. This would provide a way for science to be more widely appreciated, useful and applicable. [ABSTRACT FROM AUTHOR]

Geoforensic techniques are being deployed in searches for hidden objects to counteract the shortcomings of conventional blunderbuss methods. Processing of crime scenes during searches for clandestine graves and buried objects is often destructive. Manual excavation and other invasive methods are restricted in many contemporary situations, and the location of a body is essential for forensic investigations. Geoforensics and geophysical surveys are important tools for assisting law enforcement agencies in locating crime scenes, clandestine graves, drugs, artifacts, hazardous waste, and illegal weapons and ammunitions stored underground in preparation for terrorist attacks. Geoscience search techniques such as the geoforensic search strategy are among many models used to help find mass graves, locate missing persons, and verify information acquired from incomplete intelligence. Trace amounts of soils, sediments, and other geological materials can provide geolocations and aid in the development of a primary search area. Forensic geoscience techniques and equipment such as metal detectors, magnetic surveys, electromagnetic conductivity surveys, ground penetrating radar surveys, augering (probing), detector dogs surveys, and gravity and seismic fluctuation monitoring are discussed in this paper. In addition to the location of potential graves and ambush sites, the soil beneath the decomposing cadavers can be used to predict the postmortem interval for the deceased. Soil information and geo-mapping data can provide productive intelligence for military and national security agencies. Antiquities crimes and crimes involving gemstones in which the evidence passes through many hands can be traced back to the place of origin by checking for their geo-morphology. Serious crimes, including murder, genocide, and terrorism, can be prevented by the use of operational and decisive geoforensic techniques. This paper highlights the multidisciplinary information exchange that occurs between forensic burial science, forensic geology, and trace evidence in criminal investigations. The paper also focuses on geoforensic approaches to clandestine grave searching, underwater investigations, forensic engineering fallacies, military intelligence, ambush detection, and weapons mining.

We synthesized La2NiO4 nanostructures using the cationic surfactant-based reverse micellar route and reported on the effect of the size and shape of the La2NiO4 nanostructures on their magnetic and photoelectrochemical properties. We satisfactorily refined the powder X-ray diffraction data in the tetragonal space group, I4/mmm. Magnetic susceptibility measurements were performed on all samples within the range of 5–300 K. The Curie–Weiss law determines the magnetic susceptibility of bulk La2NiO4, and a negative value for the Weiss temperature indicates antiferromagnetic exchange. The field-dependent magnetization curves of bulk La2NiO4 suggest a canted antiferromagnetic behaviour. The Mott–Schottky plot demonstrates that La2NiO4 is a p-type semiconducting material with holes as the primary charge carriers. Chronoamperometric measurements for these nanomaterials demonstrate excellent photostability of photocurrent. [ABSTRACT FROM AUTHOR]

Magnetic powder is regarded as an effective and economical tracer for estimating soil erosion. However, the principle and application for using magnetic powder to estimate soil erosion are still not fully developed. In this study, magnetic powders with mean diameters of both 30 and 1 μm were mixed into three soils at different mass proportion. The relationship between magnetic susceptibility and the mass proportion of the introduced magnetic powder in the tagged soil, and the binding ability of magnetic powder to soil particles after both dry and wet sieving were investigated. The accuracy of tracking soil loss by using magnetic powder as a tracer was assessed. The results showed that there was a significant linear relationship between the magnetic susceptibility and the mass proportion of the introduced magnetic powder in the tagged soil. The relationship between the amount of soil captured by a magnet and the mass proportion of magnetic powder in the tagged soil indicated that soils were readily magnetized by magnetic powder, especially fine fractions. The magnetic susceptibility of magnetic powder in different sizes of soil aggregates was variable. A majority of magnetic powder of both 30 and 1 μm diameters was strongly bound with fine particles

Magnetism in Croatian caves has been significantly underexplored, despite the well-documented preservation of cave sediments. This study investigates whether magnetic susceptibility can be effectively recorded in Croatian caves and, if so, whether there are differences between in situ and laboratory measurements, as well as the extent of these differences. The focus is on two prominent sites within the Velebit Mountain range of the Dinaric Karst: the deep Slovačka Cave and the extensive Crnopac Cave System (ex. Kita Gaćešina Cave). Magnetic susceptibility was measured in soft sediments using the Kappameter KM-7 for in situ assessments and the Bartington MS2B System for laboratory analyses. The comparison of the two devices aimed to evaluate the feasibility of detecting magnetic susceptibility variations within carbonate sediments. Sampling locations were selected based on preliminary assessments of magnetic susceptibility variations and accessibility for sampling. Characteristic samples from each profile underwent X-ray powder diffraction analysis. Results revealed significant variations in magnetic susceptibility across each profile under both in situ and laboratory conditions. In situ measurements ranged from −45 × 10−5 SI to 120 × 10−5 SI, while laboratory measurements ranged from 4.00 × 10−5 SI to 99.40 × 10−5 SI. The portable Kappameter KM-7 provided satisfactory results for preliminary investigations, while the Bartington MS2B System demonstrated high precision in analyzing these variations in detail. These findings support the potential for further investigations into magnetic susceptibility in karst cave environments, with an emphasis on understanding depositional history and the timeline of climate and tectonic changes. [ABSTRACT FROM AUTHOR]

Three samples of aqueous magnetic fluids based on magnetite particles stabilized with double layers of surfactants have been synthesized. The samples have been stabilized with lauric and oleic acids, as well as their salts, taken in three different combinations. The viscosity of the synthesized samples has been measured as depending on the concentration, temperature, and shear rate. With increasing temperature, the viscosity of a sample of the fluid stabilized with a double layer of lauric acid does not decrease relative to the viscosity of water, as has been previously observed for classical magnetic fluids, but rather increases. For a sample stabilized with two layers of lauric and oleic acids, the temperature dependence of the relative viscosity is nonmonotonic. The relative viscosity of a sample stabilized with a double layer of oleic acid is actually independent of temperature. To determine the concentrations of the samples, measurements of magnetization curves were carried out followed by their granulometric analysis. It has been found that the dispersity of the samples remains unchanged upon dilution. The initial magnetic susceptibility of the fluid samples has been shown to increase with concentration more slowly than it has been predicted by the modified effective field model. In contrast to the effective field model (and other ones), the coefficient at the quadratic term in the expansion of the initial susceptibility in terms of the Langevin susceptibility has turned out to be significantly lower than 1/3. Thus, new theories of dipole–dipole interparticle interaction must be developed to describe the properties of magnetic fluids stabilized with double layers of surfactants. [ABSTRACT FROM AUTHOR]

The magnetic properties of Aurivillius-phase Bi7Fe3Ti3O21 (BFT) and Bi7−xGdxFe3Ti3O21, where x = 0.2, 0.4, and 0.6 (BGFT), were investigated. Ceramic material undoped (BGF) and doped with Gd3+ ions were prepared by conventional solid-state reaction. In order to confirm that the obtained materials belong to Aurivillius structures, XRD tests were performed. The XRD results confirmed that both the undoped and the gadolinium-doped materials belong to the Aurivillius phases. The qualitative chemical composition of the obtained materials was confirmed based on EDS tests. The temperature dependences of magnetization and magnetic susceptibility were examined for the ceramic material both undoped and doped with Gd3+ ions. The measurements were taken in the temperature range from T = 10 K to T = 300 K. Using Curie's law, the value of the Curie constant was determined, and on its basis, the number of iron ions that take part in magnetic processes was calculated. The value of Curie constant C = 0.266 K, while the concentration of iron ions Fe3+, which influence the magnetic properties of the material, is equal 3.7 mol% (for BFT). Hysteresis loop measurements were also performed at temperatures of T = 10 K, T = 77 K, and T = 300 K. The dependence of magnetization on the magnetic field was described by the Brillouin function, and on its basis, the concentration of Fe3+ ions, which are involved in magnetic properties, was also calculated (3.4 mol% for BFT). Tests showed that the material is characterized by magnetic properties at low temperatures. At room temperature (RT), it has paramagnetic properties. It was also found that Gd3+ ions improve the magnetic properties of tested material. [ABSTRACT FROM AUTHOR]

SUMMARY: Magnetic susceptibility behaviour around the Verwey transition of magnetite (≈125 K) is known to be sensitive to stress, composition and oxidation. From the isotropic point (≈130 K) to room temperature, decreasing magnetic susceptibility indicates an increase in magnetocrystalline anisotropy. In this study, we present a model which numerically analyses low-temperature magnetic susceptibility curves (80–280 K) of an experimentally shocked (up to 30 GPa) and later heated (973 K) magnetite ore. To quantify variations of the transition shape caused by both shock and heating, the model statistically describes local variations in the Verwey transition temperature within bulk magnetite. For the description, Voigt profiles are used, which indicate variations between a Gaussian and a Lorentzian character. These changes are generally interpreted as variations in the degree of correlation between observed events, that is between local transition temperatures in the model. Shock pressures exceeding the Hugoniot elastic limit of magnetite ($ \ge $ 5 GPa) cause an increase in transition width and Verwey transition temperature, which is partially recovered by heat treatment. Above the Verwey transition temperature, susceptibility variations related to the magnetocrystalline anisotropy are described with an exponential approach. The room temperature magnetic susceptibility relative to the maximum near the isotropic point is reduced after shock, which is related to grain size reduction. Since significant oxidation and cation substitution can be excluded for the studied samples, variations are only attributed to changes in elastic strain associated with shock-induced deformation and annealing due to heat treatment. The shocked magnetite shows a high correlation between local transition temperatures which is reduced by heat treatment. The model allows a quantitative description of low-temperature magnetic susceptibility curves of experimentally shocked and subsequently heat-treated polycrystalline magnetite around the Verwey transition temperature. The curves are accurately reproduced within the experimental uncertainties. Further applications for analysing magnetite-bearing rocks seem possible if model parameters, such as for oxidation are included into the model. [ABSTRACT FROM AUTHOR]

Metallic biomaterials, such as stainless steels, cobalt–chromium–molybdenum (Co–Cr–Mo) alloys, and titanium (Ti) alloys, have long been used as load-bearing implant materials due to their metallic mechanical strength, corrosion resistance, and biocompatibility. However, their magnetic susceptibility and elastic modulus of more than 100 GPa significantly restrict their therapeutic applicability. In this study, spinodal Zr 60 Nb 40 , Zr 50 Nb 50 , and Zr 40 Nb 60 (at.%) alloys were selected from the miscibility gap based on the Zr–Nb binary phase diagram and prepared by casting, cold rolling, and aging. Their microstructure, mechanical properties, corrosion resistance, magnetic susceptibility, and biocompatibility were systematically evaluated. Spinodal decomposition to alternating nanoscale Zr-rich β 1 and Nb-rich β 2 phases occurred in the cold-rolled Zr–Nb alloys during aging treatment at 650 °C. In addition, a minor amount of α phase was precipitated in Zr 60 Nb 40 due to the thermodynamic instability of the Zr-rich β 1 phase. Spinodal decomposition significantly improved the mechanical strength of the alloys due to nanosized dual-cubic reinforcement. The Zr–Nb alloys showed an electrochemical corrosion rate of 94–262 nm per year in Hanks' solution because of formation of dense passive films composed of ZrO 2 and Nb 2 O 5 during the polarization process. The magnetic susceptibilities of the Zr–Nb alloys were significantly lower than those of commercial Co–Cr–Mo and Ti alloys. The cell viability of the Zr–Nb alloys was more than 98 % toward MC3T3-E1 cells. Overall, the spinodal Zr–Nb alloys have enormous potential as bone-implant materials due to their outstanding overall mechanical properties, extraordinary corrosion resistance, low magnetic susceptibility, and sufficient bicompatibility. This work reports on spinodal Zr–Nb alloys with heterostructure. Spinodal decomposition significantly improved their mechanical strength due to the nanosized dual-cubic reinforcement. The Zr–Nb alloys showed large corrosion resistance in Hanks' solution because of formation of dense passivation films composed of ZrO 2 and Nb 2 O 5 during the polarization process. The magnetic susceptibilities of the Zr–Nb alloys were significantly lower than those of commercial Co–Cr–Mo and Ti alloys. The cell viability of the Zr–Nb alloys was more than 98 % toward MC3T3-E1 cells. The results demonstrate that spinodal Zr–Nb alloys have enormous potential as bone-implant materials due to their outstanding overall mechanical properties, high corrosion resistance, low magnetic susceptibility, and sufficient biocompatibility. [Display omitted] [ABSTRACT FROM AUTHOR]

The article investigates the effect of the specific magnetic susceptibility χ0 of 06ХН28МДТ alloy (similar to AISI 904L steel) on its corrosion behaviour in recycled water of enterprises, which most often has a pH of 4-8 and a chloride concentration of up to 600 mg/l. Under such conditions, heat exchangers made of this alloy melt can be subject to pitting. Their resistance to pitting corrosion is estimated by means of the critical temperatures (CPT) in modelrecycled water with the following parameters. In particular, it has been found that the chlorides' concentration within them has a more intense effect on the alloy CPT than their pH, since it increases up to 8°C with an increase in pH from 4 up to 8 and up to 11°C with a decrease in chlorides' concentration from 600 down to 350 mg/l. It is found that, in the model recycled water with pH 4 and chlorides' concentration of 350 mg/l, the CPT of the alloy decreases from 53°C down to 46°C, and with chlorides' concentration of 600 mg/l from 42°C down to 38°C with an increase in its parameter χ0 from 2.86 m³/kg up to 3.09 m³/kg. However, its further increase up to 3.38 m³/kg contributes to the elevation of the CPT up to 49°C in media with pH 4 and 350 mg/l and up to 40°C with pH 4 and 600 mg/l. This corrosion behaviour of the alloy is due to the synergistic effect of the alloy high χ0, the maximum content of titanium nitrides and sulphides, and the characteristic features of the selective dissolution of ΔCr, ΔNi and ΔFe from pits. In particular, under such conditions, they are stable and develop steadfastly, since the coefficients of selective dissolution of Cr ZCr < 1 and Ni ZNi > 1. [ABSTRACT FROM AUTHOR]

The Pan‐African mobile zone, situated at the margin of the Congo Craton in Cameroon, is characterized by a geological setting with polyphased tectonics, which can be summarised as the alternation of compression and extension events. The present study, conducted in a portion of the aforementioned zone, is aimed at investigating crustal structures using aeromagnetic data. To achieve this, a variety of advanced analysis and interpretation techniques were applied to reduce aeromagnetic data at the equator, including total horizontal derivative (THD), Centre for Exploration Targeting (CET), 3D Euler deconvolution (ED), spectral analysis, and 2D3/4 modeling. The results indicate that the study area can be divided into four magnetic units based on the magnetic properties (magnetic susceptibility, geometry, and depth) of the underlying rocks. The THD method reveals the presence of pseudocircular and linear structures, which are associated with mafic intrusions and faults, respectively. The structural trends of the lineament generated semiautomatically using the CET method suggest that the structures are oriented in order of priority: E‐W, WNW‐ESE, ENE‐WSW, and NE‐SW. These directions are probably related to the Pan‐African orogeny. According to the ED, the depths of these lineaments extend beyond 1250 m. A spectral analysis conducted on a profile intersecting some of the significant anomalies on the reduction to the equator (RTE) map indicates that the average depths of superficial and deep magnetic sources along this profile are approximately 0.5 and 6.5 km, respectively. The geological model obtained along this profile by direct 2D3/4 modeling indicates the presence of an ancient granitic basement, which is overlain by younger formations belonging to the Pan‐African. [ABSTRACT FROM AUTHOR]

Resting cerebral perfusion metrics can be calculated from the MRI ΔR2* signal during the first passage of an intravascular bolus of a Gadolinium-based contrast agent (GBCA), or more recently, a transient hypoxia-induced change in the concentration of deoxyhemoglobin ([dOHb]). Conventional analysis follows a proxy process that includes deconvolution of an arterial input function (AIF) in a tracer kinetic model. We hypothesized that the step reduction in magnetic susceptibility accompanying a step decrease in [dOHb] that occurs when a single breath of oxygen terminates a brief episode of lung hypoxia permits direct calculation of relative perfusion metrics. The time course of the ΔR2* signal response enables both the discrimination of blood arrival times and the time course of voxel filling. We calculated the perfusion metrics implied by this step signal change in seven healthy volunteers and compared them to those from conventional analyses of GBCA and dOHb using their AIF and indicator dilution theory. Voxel-wise maps of relative cerebral blood flow and relative cerebral blood volume had a high spatial and magnitude congruence for all three analyses (r > 0.9) and were similar in appearance to published maps. The mean (SD) transit times (s) in grey and white matter respectively for the step response (7.4 (1.1), 8.05 (1.71)) were greater than those for GBCA (2.6 (0.45), 3.54 (0.83)) attributable to the nature of their respective calculation models. In conclusion we believe these calculations of perfusion metrics derived directly from ΔR2* have superior merit to calculations via AIF by virtue of being calculated from a direct signal rather than through a proxy model which encompasses errors inherent in designating an AIF and performing deconvolution calculations. [ABSTRACT FROM AUTHOR]

Superconductivity in quasicrystals poses a new challenge in condensed matter physics. We measured the resistance and ac magnetic susceptibility of a Ta1.6Te dodecagonal quasicrystal, which is superconducting below Tc ~ 1 K. We show that the upper critical field increases linearly with a large slope of − 4.4 T/K with decreasing temperature down to 0.04 K, with no tendency to level off. The extrapolated zero-temperature critical field exceeds the Pauli limit by a factor of 2.3. We also observed flux-flow resistance with thermally activated behavior and an irreversibility field that is distinct from the upper critical field. We discuss these peculiarities in terms of the nonuniform superconducting gap and spin-orbit interaction in quasicrystal structures. [ABSTRACT FROM AUTHOR]

How does the brain process the faces of familiar people? Neuropsychological studies have argued for an area of the temporal pole (TP) linking faces with person identities, but magnetic susceptibility artifacts in this region have hampered its study with fMRI. Using data acquisition and analysis methods optimized to overcome this artifact, we identify a familiar face response in TP, reliably observed in individual brains. This area responds strongly to visual images of familiar faces over unfamiliar faces, objects, and scenes. However, TP did not just respond to images of faces, but also to a variety of high-level social cognitive tasks, including semantic, episodic, and theory of mind tasks. The response profile of TP contrasted with a nearby region of the perirhinal cortex that responded specifically to faces, but not to social cognition tasks. TP was functionally connected with a distributed network in the association cortex associated with social cognition, while PR was functionally connected with face-preferring areas of the ventral visual cortex. This work identifies a missing link in the human face processing system that specifically processes familiar faces, and is well placed to integrate visual information about faces with higher-order conceptual information about other people. The results suggest that separate streams for person and face processing reach anterior temporal areas positioned at the top of the cortical hierarchy. [ABSTRACT FROM AUTHOR]

The spin-1/2 Ising-Heisenberg branched chain, inspired by the magnetic structure of three isostructural polymeric coordination compounds [(Tp)2Fe2(CN)6X (bdmap)Cu2(H2O)] ⋅ H2O to be further denoted as Fe2Cu2 (Tp = tris(pyrazolyl)hydroborate, bdmapH = 1,3-bis(dimethylamino)-2-propanol, HX = acetic acid, propionic acid or trifluoroacetic acid), is rigorously studied using the transfer-matrix method. The overall ground-state phase diagram reveals three distinct phases: a quantum antiferromagnetic phase, a quantum ferrimagnetic phase and a classical ferromagnetic phase. In the zero-temperature magnetization curve, two quantum ground states are manifested as intermediate plateaus at zero and half of the saturation magnetization, while the magnetization reaches its saturated value within the classical ferromagnetic phase. The bipartite entanglement between nearest-neighbor Heisenberg spins is more pronounced in the quantum ferrimagnetic phase compared to the quantum antiferromagnetic phase due to a fully polarized nature of the Ising spins. A reasonable agreement between theoretical predictions for the spin-1/ 2 Ising-Heisenberg branched chain and experimental data measured for a temperature dependence of the magnetic susceptibility and a low-temperature magnetization curve suggests strong antiferromagnetic coupling between nearest-neighbor Cu2+-Cu2+ magnetic ions and moderately strong ferromagnetic coupling between nearest-neighbor Cu2+-Fe3+ magnetic ions in the polymeric compounds Fe2Cu2. A thermal entanglement between nearestneighbor Cu2+-Cu2+ magnetic ions persists up to a relatively high threshold temperature T ≈ 224 K and undergoes a transient magnetic-field-driven strengthening. [ABSTRACT FROM AUTHOR]

The intricate nature of magnetism in uranium-based Kondo lattices is a consequence of correlations between U-5f and conduction electrons. Previously, the source of magnetism has been ascribed to either Mott physics or Ruderman-Kittel-Kasuya-Yosida interaction, both of which are not fully applicable to uranium-based Kondo lattices. Using linearized quasiparticle self-consistent GW plus dynamical mean-field theory, we demonstrate a crossover from incoherent to coherent f-d Kondo cloud in the paramagnetic phase of UTe2, USbTe and USbSe. As the transition occurs, we observe an augmented f-d coherence and Pauli-like magnetic susceptibility, with a substantial frozen magnetic moment of U-5f persisting. We show that momentum dependent f-d hybridization is responsible for the magnetic moments arising from the renormalized f electrons' van Hove singularity. Our findings provide a perspective to explain the dual nature of magnetism and the long-range magnetic ordering induced by pressure in UTe2. This work aims at clarifying the puzzling magnetism of several U intermetallics, in particular the pressure-induced magnetism of UTe2. By an ab initio treatment of electronic correlations, the authors show that a momentum dependent f-d hybridization is responsible for the magnetic moments arising from the van Hove singularity of renormalized f electrons. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is the most common acquired inflammatory and demyelinating disease in adults. The conventional diagnostic of MS and the follow-up of inflammatory activity is based on the detection of hyperintense foci in T2 and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) and lesions with brain–blood barrier (BBB) disruption in the central nervous system (CNS) parenchyma. However, T2/FLAIR hyperintense lesions are not specific to MS and the MS pathology and inflammatory processes go far beyond focal lesions and can be independent of BBB disruption. MRI techniques based on the magnetic susceptibility properties of the tissue, such as T2*, susceptibility-weighted images (SWI), and quantitative susceptibility mapping (QSM) offer tools for advanced MS diagnostic, follow-up, and the assessment of more detailed features of MS dynamic pathology. Susceptibility-weighted techniques are sensitive to the paramagnetic components of biological tissues, such as deoxyhemoglobin. This capability enables the visualization of brain parenchymal veins. Consequently, it presents an opportunity to identify veins within the core of multiple sclerosis (MS) lesions, thereby affirming their venocentric characteristics. This advancement significantly enhances the accuracy of the differential diagnostic process. Another important paramagnetic component in biological tissues is iron. In MS, the dynamic trafficking of iron between different cells, such as oligodendrocytes, astrocytes, and microglia, enables the study of different stages of demyelination and remyelination. Furthermore, the accumulation of iron in activated microglia serves as an indicator of latent inflammatory activity in chronic MS lesions, termed paramagnetic rim lesions (PRLs). PRLs have been correlated with disease progression and degenerative processes, underscoring their significance in MS pathology. This review will elucidate the underlying physical principles of magnetic susceptibility and their implications for the formation and interpretation of T2*, SWI, and QSM sequences. Additionally, it will explore their applications in multiple sclerosis (MS), particularly in detecting the central vein sign (CVS) and PRLs, and assessing iron metabolism. Furthermore, the review will discuss their role in advancing early and precise MS diagnosis and prognostic evaluation, as well as their utility in studying chronic active inflammation and degenerative processes. [ABSTRACT FROM AUTHOR]

Steel slag can separate inert minerals by the mineral separation method and prevent the hydration of active minerals caused by wet magnetic separation. In order to solve the problems of low specific magnetic susceptibility, small grain size, and difficult separation of inert minerals in steel slag, fluidized dry magnetic network separation equipment was used in this study. Through the study of the influence of operating parameters, such as magnetic mesh aperture, fluidized gas speed, and background magnetic field strength in the equipment, the Longang steel slag (converter steel slag, treated by the hot disintegrating method) was effectively separated. The results show that the total iron content of the final product scavenging product decreased from 16.90 to 11.93 wt. %, which accounted for 56.16 wt. % of the total weight of the raw material, which is used as a cementitious material to replace part of the cement. The total iron content of the concentrate product increased more than twice from 16.90 to 34.27 wt. %, which accounted for 3.36 wt. % of the total weight of the raw material, which is used as ironmaking raw material through subsequent treatment. Through this study, the steel slag is effectively separated and utilized. [ABSTRACT FROM AUTHOR]

In MRI, researchers have long endeavored to effectively visualize myelin distribution in the brain, a pursuit with significant implications for both scientific research and clinical applications. Over time, various methods such as myelin water imaging, magnetization transfer imaging, and relaxometric imaging have been developed, each carrying distinct advantages and limitations. Recently, an innovative technique named as magnetic susceptibility source separation has emerged, introducing a novel surrogate biomarker for myelin in the form of a diamagnetic susceptibility map. This paper comprehensively reviews this cutting-edge method, providing the fundamental concepts of magnetic susceptibility, susceptibility imaging, and the validation of the diamagnetic susceptibility map as a myelin biomarker that indirectly measures myelin content. Additionally, the paper explores essential aspects of data acquisition and processing, offering practical insights for readers. A comparison with established myelin imaging methods is also presented, and both current and prospective clinical and scientific applications are discussed to provide a holistic understanding of the technique. This work aims to serve as a foundational resource for newcomers entering this dynamic and rapidly expanding field. [ABSTRACT FROM AUTHOR]

The three-dimension (3D) inversion of magnetic data is an effective method of recovering underground magnetic susceptibility distributions using magnetic anomaly data. The conventional regularization inversion method has good data fitting; however, its inversion model has the problem of a poor model-fitting ability due to a low depth resolution. The 3D inversion method based on deep learning can effectively improve the model-fitting accuracy, but it is difficult to guarantee the data-fitting accuracy of the inversion results. The loss function of traditional deep learning 3D inversion methods usually adopts the metric of the absolute mean squared error (MSE). In order to improve the accuracy of the data fitting, we added a forward-fitting constraint term (FFit) on the basis of the MSE. Meanwhile, in order to further improve the accuracy of the model fitting, we added the Dice coefficient to the loss function. Finally, we proposed a multi-constraint deep learning 3D inversion method based on UNet++. Compared with the traditional single-constraint deep learning method, the multi-constraint deep learning method has better data-fitting and model-fitting effects. Then, we designed corresponding test models and evaluation metrics to test the effectiveness and feasibility of the method, and applied it to the actual aeromagnetic data of a test area in Suqian City, Jiangsu Province. [ABSTRACT FROM AUTHOR]

Kagome lattice has been actively studied for the possible realization of frustration-induced two-dimensional flat bands and a number of correlation-induced phases. Currently, the search for kagome systems with a nearly dispersionless flat band close to the Fermi level is ongoing. Here, by combining theoretical and experimental tools, we present Sc3Mn3Al7Si5 as a novel realization of correlation-induced almost-flat bands in the kagome lattice in the vicinity of the Fermi level. Our magnetic susceptibility, 27Al nuclear magnetic resonance, transport, and optical conductivity measurements provide signatures of a correlated metallic phase with tantalizing ferromagnetic instability. Our dynamical mean-field calculations suggest that such ferromagnetic instability observed originates from the formation of nearly flat dispersions close to the Fermi level, where electron correlations induce strong orbital-selective renormalization and manifestation of the kagome-frustrated bands. In addition, a significant negative magnetoresistance signal is observed, which can be attributed to the suppression of flat-band-induced ferromagnetic fluctuation, which further supports the formation of flat bands in this compound. These findings broaden a new prospect to harness correlated topological phases via multiorbital correlations in 3d-based kagome systems. Kagome materials host nearly dispersionless electronic bands, but an ideal flat band close to the Fermi level is difficult to realize. Here the authors report evidence for a flat band near the Fermi level and flat-band-originated ferromagnetic fluctuation induced by orbital selective correlations in Sc3Mn3Al7Si5. [ABSTRACT FROM AUTHOR]

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

A new iron(III) complex (Et3NH)2[Fe(L)2](ClO4)·MeOH (1) where H2L = 2-{(E)-[2-hydroxyphenyl)imino]methyl}phenol has been synthesised and characterised by single crystal XRD, elemental analysis and DC magnetic susceptibility measurements. The dianionic ligands L2− coordinate in a tridentate fashion with the Fe(III) through their deprotonated phenolic oxygens and azomethine nitrogen atoms, resulting in a trans-FeO4N2 chromophore. Variable-temperature magnetic measurements were performed between 300 and 5 K under an applied field of 0.1 T and show that 1 is in the high spin state (S = 5/2) over the whole measured temperature range. This is confirmed by Mössbauer spectroscopy at 77 and 300 K. [ABSTRACT FROM AUTHOR]

Iron isotope compositions, along with the partial extraction of iron in its various forms, can be utilized to investigate the complex interplay of iron migration and transformation with respect to iron isotope patterns. This study investigated the iron composition of a typical loess-paleosol sequence in Northeast China and aimed to understand the influence of iron migration and transformation of the typical loess-paleosol sequence on iron isotopes and environmental and climatic changes that occurred in the region over time by analyzing the distribution and characteristics of iron compositions in sedimentary layers. Samples were collected from Chaoyang in Northeast China, and the iron isotopic composition was analyzed using the multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS). The findings revealed depth-dependent variations in the content of different iron forms, reflecting paleoclimatic shifts primarily through pedogenic transformation processes. Notably, iron migration within the section was observed to be limited. The variations in the reddening index and magnetic susceptibility of the loess-paleosol were primarily influenced by the presence of free iron (Fed), exhibiting a range of colors from yellow to red-yellow and red. The δ56Fe values for loess and paleosols ranged from 0.097 ± 0.035‰ to 0.167 ± 0.010‰, with an average of 0.133 ± 0.024‰ and a coefficient of variation (CV) of 15.66% at the stratum scale. These values indicated a systematic enrichment of heavy iron isotopes and a significant negative correlation with the slightly fluctuating total iron content. Specifically, our analysis highlighted distinct differences in δ56Fe values between paleosol (0.126 ± 0.024‰) and loess (0.146 ± 0.021‰). The δ56Fe in Fed was negative, averaging −0.101 ± 0.022‰, while the δ56Fe in silicate-bound iron was positive, averaging 0.156 ± 0.032‰. Intense pedogenesis, driven by warm and wet climates, facilitated iron transformations and migrations, resulting in the accumulation of light iron isotopes in the paleosols. These transformations and migrations were predominantly observed in microdomains characterized by iron depletions and concentrations, as reflected in the profile morphologies. However, the limited iron transformations and migrations did not result in significant Fe redistribution within the soil section, as evidenced by the limited variations in δ56Fe with soil depth at the stratum scale. Sampling from the stratum or pedogenic horizon could potentially create the illusion of the minimal fractionation of iron isotopes within the sequence. Therefore, a detailed examination of the iron isotope composition in the micro-domains of the loess-paleosol sequence is crucial to elucidate the fractionation processes and mechanisms of iron isotopes during the formation of these sequences. [ABSTRACT FROM AUTHOR]