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Chemical methods for the extraction and refinement of technologically critical rare earth elements (REEs) are energy-intensive, hazardous, and environmentally destructive. Current biobased extraction systems rely on extremophilic organisms and generate many of the same detrimental effects as chemical methodologies. The mesophilic methylotrophic bacterium Methylobacterium extorquens AM1 was previously shown to grow using electronic waste by naturally acquiring REEs to power methanol metabolism. Here we show that growth using electronic waste as a sole REE source is scalable up to 10 L with consistent metal yields without the use of harsh acids or high temperatures. The addition of organic acids increases REE leaching in a nonspecific manner. REE-specific bioleaching can be engineered through the overproduction of REE-binding ligands (called lanthanophores) and pyrroloquinoline quinone. REE bioaccumulation increases with the leachate concentration and is highly specific. REEs are stored intracellularly in polyphosphate granules, and genetic engineering to eliminate exopolyphosphatase activity increases metal accumulation, confirming the link between phosphate metabolism and biological REE use. Finally, we report the innate ability of M. extorquens to grow using other complex REE sources, including pulverized smartphones, demonstrating the flexibility and potential for use as a recovery platform for these critical metals.

Laser‐quality yttrium‐aluminum garnet single crystals doped with neodymium (YAG:Nd) of a concentration up to 1 at. % is grown by the method of horizontal directional crystallization from a molybdenum crucible in the protective reducing atmosphere based on argon, СО, and hydrogen. It is found that the content of carbon impurity in the grown crystals does not exceed 5·10−3 wt %, the content of molybdenum being on the level of 1.5·10−3 wt %. The optical quality of the crystals depends on the composition of the growth atmosphere and annealing. It is shown that, besides the bands of neodymium ion absorption, the crystals are characterized by the intense absorption in the UV edge of the spectrum at 370 nm wavelength, and by the wide absorption band with a maximum at 580 nm caused by formation of F and F+‐centers. The absorption at 370 and 580 nm can be eliminated by annealing. The structure perfection of the crystals is characterized by the rocking curve half‐width (β) which value varies within the limits of 10–14 arc. sec for (001) plane. Laser testing demonstrates the parameters comparable with those of YAG:Nd crystals grown by the Czochralski method from iridium crucible. [ABSTRACT FROM AUTHOR]

The composition of solid solutions in the KNd(SO4)2·H2O–SrSO4·0.5H2O system, synthesized from aqueous solutions of KCl, NdCl3, SrCl2, and H2SO4, was studied by X-ray fluorescence spectrometry. Coefficients of calibration dependences for intensity vs. element concentrations were calculated for Nd, Sr, and K by the least-squares technique. A linear approximation function was used in determining potassium and a parabolic approximation function was recommended in determining neodymium and strontium. The obtained dependences are characterized by low (<1%) relative approximation errors. In the analytical ranges (wt %) for K 0.863−8.892, Sr 8.41−38.03, and Nd 5.296−29.30, the standard deviations were 0.012−0.028, 0.008−0.098, and 0.05−0.27 respectively. [ABSTRACT FROM AUTHOR]

A new heterometallic complex of CoII and NdIII with phenathroline [Co(Phen)3][Nd(NO3)5(H2O)][Nd(NO3)4(H2O)2]⋅H2O was synthesized for the first time by the self-assembly method. The crystal structure of the complex was determined by X-ray crystallography. The compound is an anion-cation complex and crystallizes in the monoclinic space group P21/n with unit cell parameters à=12.4251(4) Å, b=11.7206(3) Å, c=36.5374(12) Å, α=γ=900, β=90.581(3)0 . In the crystalline phase, the complex is in the form of a crystal hydrate with a composition of 1:1. The anionic part of the complex consists of two nitrate hydrated NdIII complexes: [Nd(NO3)5(H2O)][Nd(NO3)4(H2O)2]–, in which the coordination number of neodymium is 11 and 10, respectively. The [Co(Phen)3]3+ ion is a cationic part of the complex in which the CoII atom has a distorted CoN6 octahedral environment, bidentately coordinating three phenanthroline molecules. Due to intermolecular hydrogen bonds (N–H⋅⋅⋅O, O–H⋅⋅⋅O), a three-dimensional supramolecular architecture is formed in the crystal, in which the polymer layers are packed parallel along the crystallographic axis a. [ABSTRACT FROM AUTHOR]

This article discusses our investigations into the structural and spectroscopic properties of Nd3+ co-doped alumino-silicate glass prepared by an in-situ sol-gel method. Structural characterization was carried out using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The XRD analysis reveals that the material is still amorphous even after being heated to 900 °C. FTIR analysis was used to identify the functional groups of the produced sol-gel silicate glass. The optical absorption spectra from the ground state 4I9/2 show seven peaks in the UV-VIS and NIR regions. The optical absorption spectrum of Nd3+ co-doped alumino-silicate glass-ceramic was used to determine the Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6). The photoluminescence (PL) spectrum was recorded with a 2W diode laser source of 808 nm excitations. From the larger stimulated emission cross-section (3.80 x 10−20 cm2) of the 4F3/2 → 4I11/2 transition, it is concluded that the SiNdAl glasses could be highly useful for the development of solid state laser materials. From the observed refractive indices at three different wavelengths, non-linear parameters for the glass, such as the Abbe number (υAb) and non-linear refractive index (n2), are derived. Highlights: Nd3+ ions co-doped with alumino-silicate glass is prepared by in-situ sol-gel methods. Red-shift in absorption peaks observed after annealing due to nephelauxetic effect. The Judd–Ofelt parameter Ω2 increased and Ω6 decreased with annealing. PL intensity increases with annealing. PL intensity increases with increasing Al content. Various physical parameters like density, refractive index and non-linear polarizability are measured to investigate possible device applications of the samples. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of intercellular and cell–matrix interactions is essential for advancing our knowledge of cell biology. Existing techniques, such as fluorescence microscopy and electron microscopy, face limitations in resolution and sample preparation. Supravital lanthanoid staining provides new opportunities for detailed visualization of cellular metabolism and intercellular interactions. This study aims to describe the structure, elemental chemical, and probable origin of zones of extreme lanthanoid (neodymium) accumulation that form during preparation for scanning electron microscopy (SEM) analysis in corneal fibroblasts filopodia. The results identified three morphological patterns of neodymium staining in fibroblast filopodia, each exhibiting asymmetric staining within a thin, sharp, and extremely bright barrier zone, located perpendicular to the filopodia axis. Semi-quantitative chemical analyses showed neodymium-labeled non-linear phosphorus distribution within filopodia, potentially indicating varying phosphate anion concentrations and extreme phosphate accumulation at a physical or physicochemical barrier. Phosphorus zones labeled with neodymium did not correspond to mitochondrial clusters. During apoptosis, the number of filopodia with extreme and asymmetric phosphorus accumulation increases. Supravital lanthanoid staining coupled with SEM allows detailed visualization of intercellular and cell–matrix interactions with high contrast and resolution. These results enhance our understanding of phosphate anion accumulation and transfer mechanisms in cells under normal conditions and during apoptosis. [ABSTRACT FROM AUTHOR]

The location of the investigation area is in Oben Village, Nekamese District, Kupang Regency, East Nusa Tenggara Province with coordinates 123° 40'40” E - 123° 41'20” E and 10° 16'0” S - 10° 16'40” S. The geology of the study area is generally occupied by mixed rocks dominated by a gray clay, blackish brown, reddish brown, with foreign chunks consisting of peridotite, sedimentary rock consisting of brown and reddish reddish limestone, silt, micaceous sandstones, metamorphic rock: chlorite schist, with quartzite veins. Of the five samples analyzed, namely four samples of soil matrix and one sample of Peridotite, the following results were obtained: six rare earth elements were contained in 4 samples of the soil matrix, namely Yttrium (Y): 3.63 – 68.75 ppm, Praseudymium (Pr): 7.38 – 38.38 ppm, Scandium (Sc): 4.83 – 4.93 ppm, Lanthanum (La): 21.48 – 91.03 ppm, Cerium (Ce): 32.48 – 184.85 ppm, and Neodymium (Nd): 9.4 – 57 ppm specifically for sample 1 also contains 3 rare earth elements, namely: Gadolinium (Gd): 3.48 ppm concentration the average is lower than its abundance in nature, Samarium Sm: 13.1 ppm, and Dysprosium: (Dy): 6.88 ppm. For rock samples only contain Praseudymium (Pr): 7.78 ppm and Cerium (Ce): 87.88 ppm. [ABSTRACT FROM AUTHOR]

Research concerning coordination polymers has been intense due to their significant variability and structural stability. With this in mind, an ionic neodymium coordination polymer was synthesized, composed of an anionic one‐dimensional polymer interconnected to a cationic three‐dimensional porous polymer, poly[dodecaaquabis(μ‐pyridine‐4‐carbohydrazide‐κ2N:O)bis(μ2‐4‐sulfobenzoato‐κ2O:O′)bis(μ3‐4‐sulfobenzoato‐κ3O:O′:O′′)trineodymium(III)] catena‐poly[aquabis(μ‐pyridine‐4‐carbohydrazide‐κ2N:O)bis(μ2‐4‐sulfobenzoato‐κ2O:O′)neodymium(III)] 4.33‐hydrate, {[Nd3(C7H4O5S)4(C6H7N3O)2(H2O)12][Nd(C7H4O5S)2(C6H7N3O)2(H2O)]·4.33H2O}n. The ligands used were 4‐sulfobenzoate (PSB) and pyridine‐4‐carbohydrazide, popularly known as isoniazid (INH), an antibiotic drug. The compound crystallizes in the monoclinic space group C2/c, with Z = 4. Solid‐state calculations suggest that the crystal structure is mainly stabilized by hydrogen bonds, i.e. O—H...O and N—H...O interactions among the polymers, and by van der Waals interactions involving the organic side chains. This net is tetragonal, 2‐nodal 3,4‐connected, and can be described as the dmd (sqc 528) type. [ABSTRACT FROM AUTHOR]

Recent policy initiatives in the United States and beyond have called for decreasing reliance on China for rare earth elements and related downstream products, such as neodymium iron boron (NdFeB) magnets. Among these initiatives, recycling of rare earth elements and NdFeB magnets from electronic waste (e-waste) has emerged as an approach to reduce both import dependence on China and the environmental impacts of mining and refining these products. This paper highlights several methods for recycling NdFeB magnets from e-waste and assesses potential impacts on supply chains and the environment from the commercial adoption of these recycling techniques. [ABSTRACT FROM AUTHOR]

The Nd-mediated coordinative chain transfer polymerization (CCTP) of dienes represents one of the state-of-the-art techniques in the current synthetic rubber field. Besides having well-controlled polymerization behaviors as well as high atom economies, it also allows for the generation of highly reactive Al-capped polydienyl chain-ends, which hold great potential, yet much less explored up to date, in achieving end functionalization to mimic the structure of natural rubber. In this study, we demonstrate an efficient in situ method to realize end-functionalizing polyisoprene by introducing epoxide compounds into a CCTP system. The end functionalization efficiency was 92.7%, and the obtained polymers were systematically characterized by 1H NMR, 1H,1H-COSY NMR, DOSY NMR, and MALDI TOF. NMR studies revealed that a maximum of two EO units were introduced to the chain ends, and based on density functional theory (DFT) studies, an energy barrier of 33.3 kcal/mol was required to be overcome to open the ring of the EO monomer. Increasing the ratio of [Ip]/[Nd] resulted in gradually increased viscosities for the reaction medium and therefore gave rise to an end functionalization efficiency that decreased from 92.7% to 74.2%. The end hydroxyl group can also be readily converted to other functionalities, as confirmed by NMR spectroscopy. [ABSTRACT FROM AUTHOR]

FeNdB magnets are one of the important secondary resources containing rare earth elements (REEs). The REEs present in FeNdB magnets can be separated from other metals by double salt precipitation. In order to recover pure Nd(III) solution from the double salts, separation experiments were done with the leaching solutions of the double salts containing Ce(III), Nd(III), and Pr(III). The REEs present in the double salts were completely dissolved using 0.5 M HCl solution at room temperature. First, Ce(III) was separated by oxidative precipitation of CeO2 and Ce(OH)4 by using NaClO and NaOH as an oxidizing and neutralizing agent. Complete separation of Ce(III) from the leaching solution of the double salts was possible by controlling solution pH at 5 under the following conditions: 11 for the molar ratio of NaClO/Ce(III) and 400 rpm at 40°C for 60 min. Second, all the Nd(III) and Pr(III) ions present in the filtrate were completely extracted by using saponified D2EHPA. Third, four stages of cross-current scrubbing of the loaded D2EHPA with pure Nd(III) solution removed most of the Pr(III) from the loaded D2EHPA. Finally, pure Nd(III) solution was obtained by stripping the scrubbed D2EHPA with weak HCl solution. The optimum conditions for the extraction, scrubbing, and stripping were obtained. A simple process was proposed to recover Nd(III) solution with purity higher than 99.9% from FeNdB magnets. [ABSTRACT FROM AUTHOR]

1H NMR measurements are reported for the C6D6 solution of the complex bis(tris(tert-butyl)cyclopentadienyl)neodymium(III) iodide [Cp′′′2NdI] {where Cp′′′ = 1,3,4-tris(tert-butyl)cyclopentadienide}. Temperature dependences of the 1H NMR spectra of the complex have been analyzed using the bandshape analysis, taking into account the temperature variation of the paramagnetic chemical shifts, within the frame of the dynamic NMR method. The conformational dynamics of the complex are conditioned by the process of racemization (with the value of the Gibbs activation energy ΔG ‡298 = 58 ± 3 kJ mol−1). Due to the substantial temperature dependence of the paramagnetic shifts, the complex is essentially an NMR thermosensor reagent for local temperature monitoring. Good agreement between the calculated and experimental lanthanide-induced paramagnetic shifts in the 1H NMR spectra indicates the similarity of the structure of the complex in a solution of C6D6 and the structure in the crystalline phase, found from the data of the X-ray structural study of the similar complex. [ABSTRACT FROM AUTHOR]

The article presents methods for amplifying femtosecond laser pulses. A chirped-pulse amplification setup and a grating-based device are presented that can be used to amplify a chirped pulse with a total gain of up to 1011. A typical block diagram of a chirped-pulse amplifier for producing high-power femtosecond pulses is described. The use of an amplifying system consisting of a multipass amplifier and amplification stages with a progressive increase in the diameter of the laser beam makes it possible to increase the pulse energy by a factor of 108–109, avoiding damage to the amplifying elements. The method of amplifying chirped pulses requires the use of diffraction gratings with sizes close to 1 m to amplify pulses up to energies of tens of J. In particular, the use of giant laser systems based on amplifying cascades containing neodymium glass plates is noted. A parametric method for amplifying femtosecond pulses is considered. The advantages and disadvantages of parametric amplification are discussed. A general block diagram of an installation for obtaining petawatt-level femtosecond pulses by parametric amplification is presented. The principle of parametric amplification is used not only to obtain ultra-high powers and intensities, but also to achieve high values of other parameters. [ABSTRACT FROM AUTHOR]

Recovery of rare earth elements (REEs) from spent NdFeB magnets is important to meet the increasing demand for magnets and high-tech applications. In general, pretreatments of spent NdFeB magnets are necessary to recover REEs such as Nd, Pr, and Ce from the magnets. In this work, a simple process was proposed to recover REEs without any pretreatment of NdFeB magnets by using precipitation of REE(III) double salt. The correlations among several variables on the precipitation of REE(III) double salt were investigated by using synthetic solutions such as the molar ratio of Na(I) and sulfuric acid to Nd(III), the concentration of Nd(III) and Fe(III). The REES and iron present in NdFeB magnets were completely dissolved in 2 M H2SO4 solution at room temperature. The dissolved REE(III) ions were then directly separated by precipitation of double salt when Na2SO4 was added at 80°C. After REEs precipitation, the addition of iron powder to the filtrate at room temperature reduced Fe(III) to Fe(II) and removed a small amount of Cu(II) and Co(II) by cementation. Then Fe(II) and Na2SO4 were separated by precipitation of Fe(OH)2 when solution pH was adjusted to 8. The conditions for the precipitation of Nd(III) double salt were thermodynamically verified. Mass balance of continuous experiments indicated that it was possible to recover REEs and iron with high purity by the proposed process in this work. [ABSTRACT FROM AUTHOR]

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Abstract Rare earth elements (REEs) exhibit diagnostic absorption features in the visible-near infrared region, enabling their detection and identification via spectroscopic methods. Satellite-based remote sensing mapping of REEs, however, has not been attainable so far due to the necessity for high-quality hyperspectral data to resolve their narrow absorption features. This research leverages EnMAP hyperspectral satellite data to map REEs in Mountain Pass, California—a mining area known to host bastnaesite-Ce ore in sövite and beforsite carbonatites. By employing a polynomial fitting technique to characterize the diagnostic absorption features of Neodymium (Nd) at ∼740 and ∼800 nm, the surface occurrence of Nd was successfully mapped at a 30m pixel resolution. The relative abundance of Nd was represented using the continuum-removed area of the 800 nm feature. The resulting map, highlighting hundreds of anomalous pixels, was validated through laboratory spectroscopy, surface geology, and high-resolution satellite imagery. This study marks a major advancement in REE exploration, demonstrating for the first time, the possibility of directly detecting Nd in geologic environments using the EnMAP hyperspectral satellite data. This capability can offer a fast and cost-effective method for screening Earth’s surfaces for REE signature, complementing the existing exploration portfolio and facilitating the discovery of new resources.

This study investigates the impact of rare elements on high-entropy alloys (HEAs) and provides significant insights. By integrating varying proportions of Al-Nd and Al-Ce compounds into a CoCrFeNi-based alloy, shifts were detected in the microstructure and phase composition of grains. As the proportion of rare elements rose, their localization within the grain phase structure intensified, leading to overall coarsening. The heat transfer characteristics of HEA alloys containing rare elements exhibited variability, with notable phase transitions occurring at cryogenic temperatures based on the alloying constituents. Among the tested alloys, Ce10 and Ce20 alloys demonstrated the highest heat transfer rates (800 Wg − 1 ). Notably, an escalation in the rare element ratio added to the alloy resulted in a significant augmentation in hardness, nearly doubling the original level. [ABSTRACT FROM AUTHOR]

Neodymium magnet waste recycling and precious metal recovery have drawn a lot of researchers' attention because of their vital role in contemporary technology. In this work, the potential of citric acid for the leaching of neodymium from hard disk drive waste magnets has been examined using statistical approaches like full factorial design(FFD) and central composite design (CCD).The variables have been screened and conditions are optimized to obtain higher leaching. The polynomial quadratic Model proves effective to predict optimized conditions for neodymium leaching. Leachant concentration and temperature were screened as the most effective factors. Optimization conditions for the leaching process were achieved through central composite design, revealing that 2 mol/L citric acid and a temperature of 333 K provide the ideal conditions for the complete dissolution of neodymium. This extensive study contributes to sustainable materials management and resource conservation by illuminating the effective recovery of important metals from neodymium magnets. [ABSTRACT FROM AUTHOR]

This paper reports the spectral and kinetic features of the up- and downconversion photoluminescence (PL) of (1%, 2%, 3%, 4%, and 5%) Nd-doped BaSrSiO4 silicates to elucidate the fundamental processes of UCPL. This manuscript discusses the energy transition levels and potential excitation processes. The sol-gel method was utilized for synthesizing Nd-doped BaSrSiO4 nanocrystals, which were then annealed at 600 °C to produce silicates. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine the crystal phase and nanocrystal formation of the synthesized Nd-doped BaSrSiO4 powders. When activated by various UV–visible wavelengths, the PL downconversion (DCPL) from a sample exhibits well-resolved bands with sub-split lines centered at 890 nm associated with the near-infrared transitions in Nd3+ ions. Quenching occurred at 5% doping due to multipolar interactions, indicating that 4% doping is appropriate for temperature sensing applications. Conversely, a visible upconversion PL (UCPL) has been found when excited by a pulsed laser of 800 nm. Furthermore, the suggested energy levels for the upconversion process were verified using the UCPL and photoluminescence excitation (PLE) data. Our results imply that the excited-state absorption mechanism (ESA) in rare earth (Nd)-doped BaSrSiO4 is most likely a potential mechanism of the UCPL process. The TL glow peak shows the highest intensity for 4 mol% Nd3+-doped BaSrSiO4 at 88 °C. Quenching at 5% was observed due to the dissipation of the trapping centers. [ABSTRACT FROM AUTHOR]

Molten oxide electrolysis is a promising pathway to decarbonize primary metal production. The oxide electrolyte is less hazardous and eco‐toxic than halides (molten salt electrolysis) and, with the use of renewably generated electricity and an inert anode, oxygen is produced as a by‐product instead of CO2. Building fundamental understanding of electrolytic operating windows requires starting with simple chemistries. Here we investigate a simplified binary oxide system as an electrolyte for titanium oxide reduction to metal. The TiO2−Na2O binary system forms a eutectic, reducing the liquidus temperature over a wide composition range. FactSage 8.1 predictions suggested Ti reduction would become favorable over Na reduction for compositions greater than 0.49 mole fraction TiO2. The prediction was validated by the detection of metallic Ti after electrolysis experiments. However, the reduction efficiency was too low (0.24±0.08 % at −0.1 V vs Ti reference electrode) for the TiO2−Na2O system to be a viable industrial electrolyte for Ti production. Scoping for other binary oxide systems was performed for electrolytic production of two critical metals, tantalum and neodymium. Based on TiO2−Na2O system's predicted behavior, candidate binary oxide systems were identified that contained congruently melting line compounds flanked by eutectic reactions from the ACerS‐NIST Phase Equilibria diagrams database. [ABSTRACT FROM AUTHOR]

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The aim of this research is to investigate novel compositions of oxyfluoride glasses doped with Neodymium (Nd3+) rare earth ions in the visible spectrum. This area has not been extensively studied in the existing literature, so it is vital to understand the favorable photoluminescence characteristics within this part of the electromagnetic spectrum. Therefore, we synthesized and characterized SiO2‐PbO‐PbF2 (SPF) doped with 1% neodymium (Nd3+) ions glasses. Spectroscopic analyses, based on Judd–Ofelt theory, were conducted on absorption spectra. These analyses enabled to determine absorption cross‐sections, transition probabilities, and Judd–Ofelt intensity parameters Ω2, Ω4, and Ω6 for the different transition. Additionally, we calculated various radiative properties, such as branching ratios, integrated cross‐sections, radiative lifetimes, emission cross‐section, optical gain, and the multicolor behavior (chromaticity coordinates, CIE diagram) under different excitation wavelengths. The results suggest promising prospects for using these oxyfluoride silicate glasses doped with Nd3+ as a fluorophore, potentially for lasing materials around 630‐nm emission and in other photonic applications. [ABSTRACT FROM AUTHOR]

Aillikite dikes of carbonate–biotite composition, intersecting Paleoproterozoic banded iron formations, were discovered in the Kursk block of Sarmatia for the first time. Their age is 2.10–2.07 Ga. The aillikite dikes underwent epidote–amphibolite facies metamorphism (550°С, 2–3 kbar), and they are deformed and foliated. Primary magmatic olivine and pyroxene were not preserved. In terms of geochemistry, ultramafic lamprophyres of the Kursk block are similar to petrotypical aillikites. They are depleted in SiO2 and Al2O3 and enriched in MgO, TiO2, K2O, Cr, Ni, and Nb with highly fractionated LREE and HREE. The highly radiogenic neodymium isotopic composition is indicative of a juvenile enriched (metasomatized) mantle source of aillikites. Positive Nb and Ti anomalies suggest metasomatic alterations of the depleted lithosphere mantle by OIB melts under opening of the Tim back-arc basin. The aillikite dikes and carbonatites of the Dubravinsky complex could have been formed at different melting degrees of a single deep, lithospheric source, enriched in lithophile elements shortly before the melting episode, possibly in a suprasubduction setting about 2.1 Ga. [ABSTRACT FROM AUTHOR]

This paper presents a novel nondestructive testing system, magneto-eddy-current sensor (MECS), to enable surface profiling of dissimilar materials by combining magnetic sensing for ferromagnetic materials and eddy-current sensing for nonferromagnetic materials. The interactions between an electromagnetic field and nonferromagnetic surface and between a magnetic field and ferromagnetic surface were measured by the MECS. The MECS consists of a conic neodymium magnet and a copper coil wound around the magnet. Aluminum and steel surfaces bonded together were prepared to test nondestructive surface profiling of dissimilar materials by the MECS. The interactions between an electromagnetic field and aluminum surface were characterized by monitoring the impedance of the coil, and the interactions between a magnetic field and steel surface were characterized by using a force sensor attached to the neodymium magnet. The magnetic and electromagnetic effects were numerically analyzed by the finite element model. The developed MECS showed the following performance: measurement spot size 5 mm and 10 mm, dynamic measurement bandwidth (eddy-current sensing 1 kHz and magnetic sensing 200 Hz), measuring range 25 mm and 17 mm, polynomial fitting error 0.51% and 0.50%, and resolution 0.655 µm and 0.782 µm for nonferromagnetic and ferromagnetic surface profiling, respectively. This technique was also applied to surface profiling and inspection of the rivet joining sheet materials. The results showed that the MECS is capable of nondestructively monitoring and determining the riveting quality in a fast, large-area, low-cost, convenient manner. [ABSTRACT FROM AUTHOR]

In this study, trivalent neodymium-doped silicate-based 13–93 bioactive glass scaffolds were prepared by the robocasting method using sol-gel-derived bioactive glass powders for tissue engineering applications. Sintered scaffolds were coated by borate-based 13-93B3 bioactive glass-containing polylactide-co-glycolide solution. The produced composite scaffolds' mechanical, morphological, and structural characteristics were thoroughly examined, as their in vitro bioactivity in cell culture media and simulated body fluid. Furthermore, the scaffolds' amoxicillin adsorption and release behavior was examined over time. The outcomes demonstrated that it was feasible to effectively create periodic, mesh-like-patterned robocast glass scaffolds utilizing Nd3+-doped sol-gel-derived bioactive glass powders. The scaffolds' compressive strengths ranged from 10.02 MPa to 18.6 MPa, with the PLGA-coated scaffolds exhibiting the highest strength values. All of the scaffolds that were submerged in simulated body fluid for 28 days showed hydroxyapatite formation. The presence of borate glass on the surface of the silicate-based glass scaffolds improved the hydroxyapatite formation ability. The quantity of drug adsorption for all types of scaffolds was measured to be between 4 and 9% whereas the cumulative drug release was in the range of 58 to 96%. Borate glass particle-containing PLGA coating enhanced the drug delivery behavior. [ABSTRACT FROM AUTHOR]

Background: A ban on neodymium magnets was lifted by the U.S. Consumer Product Safety Commission in 2016. Pediatric gastroenterologists and surgeons were increasingly tasked with removing these problematic objects. The purpose of this study was to assess the utility of single-incision laparoscopic surgery (SILS) in the management of ingested magnets. Patients and Methods: This is a single-center, retrospective assessment of surgical interventions for ingested magnets. International Classification of Disease, 10th revision codes were used to identify 349 patients ≤21 years of age evaluated for foreign body ingestion over a 4.5-year period. A medical record review helped isolate 29 (8.3%) magnet ingestions, 9 requiring surgical intervention. RedCap was used for analysis. Results: Of 9 surgical patients, 7 underwent SILS intervention by 1 surgeon. Another surgeon performed an open operation, whereas a third performed a multiport operation. Of the 7 SILS cases, 3 were completed without conversion to open. In one of these cases, bowel resection with primary anastomosis was performed. For SILS cases, average operating room time was 109 minutes (38–170 minutes), time to enteral feeds was 23 hours (0.28–79.2 hours), and hospital length of stay (LOS) was 3.8 days (1.96–6.68 days). Thirty-day readmission for SILS was 14.3%. No other complications were observed. Conclusions: SILS has been safely utilized for magnet retrieval. It offers an ability to identify the affected intestinal segment and an opportunity to intervene extracorporeally through an uncapped port. In addition, knowing where matted bowel is located can direct a limited incision during conversion to laparotomy. This may confer benefits of decreased pain, shortened time to enteral feeds, and decreased hospital LOS. [ABSTRACT FROM AUTHOR]

The CaAl2SiO6 (CASO) aluminosilicate polycrystals doped with Ce3+ and Nd3+ ions have been synthesized using the sol–gel method. The XRD diffractograms, excitation and emission spectra, as well as the decay time profiles were measured and discussed. The energies of Nd3+ levels in CASO polycrystals were assigned. A series of crystalline powders were divided into two groups, with slightly different crystal symmetry. The CIE chromatic coordinates and colour purity were calculated. Refractive indices and bandgap energies were estimated. The influence of spectroscopic properties, depending on the symmetry and doping ratio, was analysed. Obtained research results explain the influence of doped ions on the spectroscopic properties of CaAl2SiO6 and provide a new perspective on aluminosilicate compounds. [ABSTRACT FROM AUTHOR]

In order to meet the demands of humanity and address the global environmental situation, it is imperative that we explore alternative energy sources and advance energy storage technology. The aim of this study was to investigate the impact of Nd-doping on the structural and electrochemical performance of FeAl2O4 nanoparticles (NPs). The successful synthesis of Nd-doped FeAl2O4 NPs) was accomplished through a simple sonication process. An evaluation was conducted on the properties of Nd-doping FeAl2O4 NPs) to determine their suitability for supercapacitor (SC) applications. Moreover, the specific capacitance (Cs) of Nd-doped FeAl2O4 NPs) reaches a maximum of 1194.69 F g−1 when subjected to a current density of 1.0 A g−1 compared to FeAl2O4 nanoparticles. Furthermore, Nd-doped FeAl2O4 NPs exhibited excellent cyclic stability and low impedance (Rct = 0.07 Ω), owing to their modified morphology, making a promising material for supercapacitor SC electrodes that offer high capacity, affordability, and environmental friendliness. Our research has validated that the synthesized material can enhance the capacitive properties of transition-metal oxides with spinel structures in new, generated energy storage devices. [ABSTRACT FROM AUTHOR]

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Lanthanoid complexes have found potential application in diverse fields including biology and medicine. The present study aim to synthesize a new dione derivative of 1-phenylacetyl-pyrrolidine-2-carboxyaldehyde and its Lanthanoid complexes and investigate their antimicrobial and antimalarial activities. The ligand 1-phenylacetyl-pyrrolidine-2-carboxyaldehyde (L) and its Lanthanoid complexes; Ce(L)3](NO3)3.2H2O,[Pr(L)3](NO3)3.2H2O, and [Nd(L)3](NO3)3.2H2Owere synthesized and their structures elucidated by spectroscopic techniques, including ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) spectroscopy, magnetic susceptibility and elemental analysis.The antimicrobial activity of the ligand and its complexes was evaluated by the agar-well diffusion method. The antimalarial activity of Nd(III) complex was assessed using the Peter’s 4-day suppressive test in mice. Acute toxicity of Nd(III) complex was evaluated using the Lorke method. The synthesized compounds exhibited UV absorption between 282-380 nm. The FTIR spectra of the compounds showed absorption peaks for carbonyl (C=O) stretch at 1691-1703 cm-1. The ¹H-NMR for the ligand and its complexes appeared as multiplets between 7.29-7.50 ppm and their 13C-NMR spectra displayed signals between 127.07-135.40 ppm, and at 173 ppm attributed to the phenyl ring and the carbonyl carbons, respectively.The magnetic susceptibility results revealed the complexes were paramagnetic. Neodymium (III) complex ([Nd(L)3](NO3)3.2H2O) exhibited the most potent antimicrobial activity inhibiting more of the test organisms than its congeners.[Nd(L)3](NO3)3.2H2Oexhibited a dose-dependent antimalarial activity with a mild to moderate reduction in percentage parasitaemia. Acute toxicity test showed an LD50value of 2,154.07 mg/kg for [Nd(L)3](NO3)3.2H2O. The complex is relatively safe and has potential for use as antimicrobial and antimalarial agent. [ABSTRACT FROM AUTHOR]

To improve our understanding and guide future studies and applications, we review the biogeochemistry of the rare earth elements (REE). The REEs, which form a chemically uniform group due to their nearly identical physicochemical properties, include the lanthanide series elements plus scandium (Sc) and yttrium (Y). These elements, in conjunction with the neodymium isotopes, are powerful tools for understanding key oceanic, terrestrial, biological and even anthropogenic processes. Furthermore, their unique properties render them essential for various technological processes and products. Here, we delve into the characteristics of REE biogeochemistry and discuss normalization procedures and REE anomalies. We also examine the aqueous speciation of REEs, contributing to a better understanding of their behavior in aquatic settings, including the role of neodymium isotopes. We then focus on their environmental distribution, fractionation, and controlling processes in different environmental systems across the land‐ocean continuum. In addition, we analyze sinks, sources, and the mobility of REEs, providing insights into their behavior in these environments. We further investigate the sources of anthropogenic REEs and their bioavailability, bioaccumulation, and transfer along food webs. We also explore the potential effects of climate change on the cycling, mobility and bioavailability of REEs, underlining the importance of current research in this evolving field. In summary, we provide a comprehensive review of REE behavior in the environment, from their properties and roles to their distribution and anthropogenic impacts, offering valuable insights and pinpointing key knowledge gaps. Key Points: Rare earth elements (REE) are powerful tracers of both natural and anthropogenic processes within terrestrial and ocean environmentsREE are controlled by absorption, adsorption/desorption, co‐precipitation, remineralization, and particle dissolutionREE are technology‐critical metals with broad applications in the future low‐carbon global economy [ABSTRACT FROM AUTHOR]

Rare earth metals are considered to be some of the most critical raw materials on the planet due to their use in many products and technologies, the difficulty in isolating the individual elements from ores and each other, and the market restrictions that threaten their supply. However, despite this, the recycling rates for rare earth metals remain low. Hydrometallurgy has been proposed to hold the greatest potential for the recovery of rare earth metals from waste materials. However, the design of hydrometallurgical processes for the recovery of rare earth elements from waste requires a good understanding of the behaviour of the rare earth metals between different phases.In this study, the distribution coefficients of two rare earth metals, yttrium, and neodymium, between an organic solvent; bis(2-ethylhexyl) phosphate, diluted in n-dodecane at between 0.25 M and 1 M; and an aqueous nitric acid solution at concentrations of between 0.1 M and 2.8 M were measured. Distribution measurements were performed using a series of liquid–liquid extraction cells at a constant temperature of 298.2 K. The concentration of the rare earth metals was measured using ICP-OES analysis. The distribution coefficients and the acid concentration were found to be inversely related to each other. Conversely, the distribution coefficients were directly proportional to the concentration of the solvent in the organic phase.The data reported in this paper will be used to design a counter-current liquid–liquid extraction column for the recovery of neodymium from waste permanent magnet powder.

Rare earth elements are a group of chemicals widely utilized in industry, leading to ecosystem contamination. Due to the lack of regulatory measures, there exists a considerable gap in knowledge concerning their potential to induce adverse effects in organisms. Zebrafish serve as a species utilized in evaluating the risk of potentially toxic substances in the aquatic ecosystem. Our objective was to evaluate the acute toxicity in zebrafish embryos induced by two of the most used rare earth elements, neodymium, categorized as a light element, and yttrium, as a heavy element. We followed OECD guideline n°. 236 "Fish Embryo Acute Toxicity Test", exposing embryos to concentrations of 6.4, 16, 40, 100, and 250 mg/L, and calculated the LC50. Our study revealed comparable LC50 values for both elements (55.58 mg/L for Nd, and 45.61 mg/L for Y), suggesting a probable similarity in toxicity. These concentrations values have previously been identified in various contaminated regions globally, presenting a cause for concern. [ABSTRACT FROM AUTHOR]

A simple, efficient, direct and economical method for the mutual separation of Nd and Pr was developed by the selective dissolution of Nd2O3 from their oxide mixtures in an ionic liquid containing 2‐thenoyltrifluoroacetone (HTTA) resulting in an unprecedented separation factor (βNd/Pr)>500, which is 277 times more than the thus far reported βNd/Pr values. The proposed mechanism was supported by DFT computations. [ABSTRACT FROM AUTHOR]

The chemical resistance of glasses based on the PbCl2–PbO–B2O3–NdF3 system was studied. Oxochloride lead-borate glasses demonstrated satisfactory water resistance and alkali resistance, while low acid resistance. Bulk glass samples were exposed to the tropical climate of Southeast Asia for a year. The spectral-luminescent characteristics of neodymium ions in these matrices maintain good stability in a tropical climate. [ABSTRACT FROM AUTHOR]

Neodymium hexaboride (NdB6) is an important rare‐earth hexaboride material that has many structural and functional applications in advanced technologies. This paper presents the results on experimental studies of synthesis, densification, microstructural characterization, and mechanical properties of NdB6. Single‐phase NdB6 powder was obtained by the carbothermic reduction of Nd2O3 and B4C at optimized conditions and charge composition. Densification of NdB6 powders was carried out by pressureless sintering and hot pressing. The highest density of 93% theoretical density (TD) was obtained at 1800°C by hot pressing for 2 h in a vacuum, whereas 79% TD was obtained by pressureless sintering at 1900°C. However, 99.9% dense NdB6 was obtained by adding a sintering aid of 5 wt.% B4C using a hot‐pressing technique at 1800°C. Microstructural characterization revealed no significant grain growth during hot pressing at 1800°C, and a dominant transgranular mode of fracture was observed in fractography. Hardness values were measured as 23.8 and 28.8 GPa, respectively, by two different techniques micro‐ and nanohardness testers. Fracture toughness and elastic modulus of hot‐pressed NdB6 sample were measured as 3.04 MPa m1/2 and 484 GPa, respectively. The flexural strength of dense NdB6 was obtained as 156 MPa by three‐point bend test. [ABSTRACT FROM AUTHOR]

The possibility of four-layer (Ni – Cu – Ni – Sn) electroplating and epoxy paint coating of a NdFeB magnet from a hard magnetic alloy used in wind generators is considered. The corrosion-protective effect of various paint coatings on the magnet in aggressive environments is determined. It is shown that the electroplate layuer should have a thickness of at least 20 µm and the epoxy paint coating should be no thinner than 15 µm. [ABSTRACT FROM AUTHOR]

A possibility of using an industrially produced anionic surfactant, alkylbenzenesulfonic acid, for the precipitation and flotation extraction of neodymium(III), erbium(III), and thulium(III) ions is investigated. The influence of the concentration and ratio of the reacting components and the concentrations of sulfuric acid and sodium hydroxide on the degree of precipitation of metal ions is considered. The composition of the resulting compounds is established and their conditional solubility products are calculated. Conditions for the flotation of metal ions with alkylbenzenesulfonic acid are optimized. [ABSTRACT FROM AUTHOR]

The chlorination mechanism of neodymium oxide for the production of anhydrous neodymium chloride was analyzed based on the reaction temperature and reaction ratio of ammonium chloride, considering the suppression of the generation of NdOCl, an intermediate product of the reaction process. The results were obtained by distinguishing the shape of the produced NdCl3 (powder and bulk) and the setup of the chlorination equipment, reflecting its sensitivity to moisture and oxygen. The powdered form of NdCl3 produced at 400 °C and under argon gas flow was identified as NdCl3·6(H2O), while the bulk form of NdCl3 produced by melting at 760 °C after a chlorination process consisted of anhydrous NdCl3 and NdCl3∙n(H2O). The powdered NdCl3 produced in an argon gas environment with a controlled level of oxygen (below 16.05 ppm) and moisture (below 0.01 ppm) content was identified as single-phase anhydrous NdCl3 and showed the highest chlorination conversion rate of 98.65%. The addition of overstoichiometric ratios of NH4Cl in the chlorination process decreased the total amount of impurities (N, H, and O) in the NdCl3 product and increased the conversion rate of NdCl3. [ABSTRACT FROM AUTHOR]

Tin chloride of 1M concentration was used as the precursor, and neodymium chloride was used as a dopant (with different doping ratios) to create pure and neodymium (Nd) doped tin oxide (SnO2) thin films with varied doping ratios (1, 3 and 5) wt%. Using UV-visible absorbance and XRD patterns, it was possible to analyze the impact of Nd doping ratio on the optical and structural characteristics of the produced thin films. All samples have a polycrystalline structure that is identical to the conventional SnO2 peaks, according to XRD measurements. As the doping ratio rises, the crystallinity falls. At doping ratio of 5wt%, a new phase emerged for Nd2O3. According to optical characteristics, the transmittance rises with doping ratio, from 4.13% to 35.76% at 550 nm. The optical band gap increases from 3.60 to 4.20eV with an increase in Nd content from 0 to 5%, and the energy gap was a direct transition. I-V properties for all samples are examined in dark and light conditions. Photocurrent and dark current increases with increasing doping ratio. The produced films have shown increase in photoconductivity gain. [ABSTRACT FROM AUTHOR]

The distribution of neodymium dopant (as surrogate for americium) within the porous network of sintered (U,Nd)O 2 microspheres prepared via a sol-gel infiltration technique was comprehensively assessed. Powder X-ray diffraction (XRD) results indicated the formation of a neodymium oxyapatite secondary phase with Nd 4.69 (SiO 4) 3 O composition, alongside the principal U 1-y Nd y O 2 face-centered cubic phase for y = 20 and 30 mol%. The hexagonal oxyapatite phase was likely formed during sintering under reducing conditions, when volatile SiO from an external contamination reacted with the Nd3+ in the microspheres. Transmission electron microscopy (TEM) analyses on lamellae prepared via focused ion beam (FIB) further confirmed a distinct phase separation between the main (fluorite U 1-y Nd y O 2) phase and the oxyapatite phase, without mutual solubility of Si and U. To gain a deeper insight into the microstructure, energy dispersive X-ray spectroscopy (EDS) and electron probe microanalysis (EPMA) were performed at different locations in cross-sectioned U 1-y Nd y O 2 microspheres. The elemental mappings showed a higher intensity of combined Nd and Si content in the periphery region, where a higher filling of the porosity network is to be expected. XRD lattice parameter analysis was found to be the most reliable method to elucidate the Nd metal fraction y in U 1-y Nd y O 2 , as compared to local quantification methods using electron beam induced X-ray fluorescence. The sintered microspheres with a targeted 20 and 30 mol% Nd dopant concentration contain around 3 ± 2 wt% and 5 ± 2 wt% Nd-oxyapatite phase. The formation mechanism of the oxyapatite phase appears to involve capillary infiltration in the liquid state, during high temperature sintering, and it may be of interest for other applications. Despite the phase heterogeneity, the method was successful in infiltrating Nd throughout the porous microspheres at high loading levels, as intended for the fabrication of transmutation targets. The distribution of the Nd-dopant throughout the microsphere was achieved as desired, and this study presents a successful fabrication and detailed characterization of porous uranium oxide microspheres doped with Nd3+, contributing to the development of transmutation target research. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, we report the synthesis of a new cubic neodymium-rhenium metallic alloy NdRe2 through the utilization of high pressure and laser heating in a diamond anvil cell. NdRe2 crystallizes in the … space group with a lattice parameter equal to 7.486 (2) Å and Z = 8 at 24 (1) GPa and 2,200 (100) K. It was studied using high-pressure single-crystal X-ray diffraction. The compound crystallizes in the cubic MgCu2 structure type. Its successful synthesis further proves that high-pressure high-temperature conditions can be used to obtain alloys holding a Laves phase structure. Ab initio calculations were done to predict the mechanical properties of the material. We also discuss the usage of extreme conditions to synthesize and study materials present in the nuclear waste. [ABSTRACT FROM AUTHOR]