Rare Earth Metals Research Articles

Rare Earth Metal Ion‐Doped Halide Solid Electrolytes plus Ta5+ Substitution for Long Cycling All‐Solid‐State Batteries

AbstractLi2ZrCl6 (LZC) solid electrolyte has been recognized as a promising candidate for all‐solid‐state batteries (ASSBs), owing to its remarkable compatibility with high‐voltage cathodes and the cost advantage among halide electrolytes. However, the ionic conductivity of LZC (≈0.4 mS cm−1) requires enhancement. Herein, rare earth metal elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Y) have been doped into LZC, resulting in a doubling of the ionic conductivity. Moreover, Ta5+ is utilized to further modulate the concentration of Li+ to enhance the ionic conductivity and reduce the dosage of expensive rare‐earth metal. Using the Li‐Zr‐Dy‐Cl component as a case study, 16 types of Dy3+ and Ta5+ co‐doped electrolytes have been synthesized and the optimal Li2.1Zr0.8Dy0.15Ta0.05Cl6 (LZDTC) exhibits the ionic conductivity of 1.67 mS cm−1. Three‐dimensional Li‐ion transport pathways in LZDTC has been revealed. The dual‐substitution of Dy and Ta at Zr site changes length of Li‐Cl bond and Li occupation, thereby reducing the resistance to Li+ migration. ASSBs of Li‐In/LGPS‐LZDTC/NCM811 demonstrate a capacity of 117 mA h g−1 after 500 cycle at 0.5 C with a 74% retention rate, highlighting the effectiveness of the dual‐doping strategy for creating superionic conductors for ASSBs.

About the Rare-Earth Metal(III) Bromide Oxoarsenates(III) RE5Br3[AsO3]4 with A- (RE = La and Ce) or B-Type Structure (RE = Pr, Nd, Sm–Tb) and RE3Br2[AsO3][As2O5] (RE = Y, Dy–Yb)

The monoclinic rare-earth metal(III) bromide oxoarsenates(III) RE5Br3[AsO3]4 of the A-type (RE = La and Ce) crystallize in the space group C2/c with the lattice parameters a = 1834.67(9) pm, b = 553.41(3) pm, c = 1732.16(9) pm and β = 107.380(3)° for La5Br3[AsO3]4 and a = 1827.82(9) pm, b = 550.67(3) pm, c = 1714.23(9) pm and β = 107.372(3)° for Ce5Br3[AsO3]4 with Z = 4, while, for the B-type (RE = Pr, Nd and Sm–Tb), they prefer the space group P2/c with lattice parameters from a = 881.23(5) pm, b = 547.32(3) pm, c = 1701.14(9) pm and β = 90.231(3)° for Pr5Br3[AsO3]4 to a = 875.71(5) pm, b = 535.90(3) pm, c = 1643.04(9) pm and β = 90.052(3)° for Tb5Br3[AsO3]4 with Z = 2. The closely related rare-earth metal(III) bromide oxoarsenates(III) RE3Br2[AsO3][As2O5] crystallize in the triclinic space group P1¯ with lattice parameters from a = 539.15(4) pm, b = 870.68(6) pm, c = 1092.34(8), α = 90.661(2)°, β = 94. 792(2)° and γ = 90.223(2)° for Dy3Br2[AsO3][As2O5] to a = 533.56(4) pm, b = 869.61(6) pm, c = 1076.70(8), α = 90.698(2)°, β = 94.785(2)° and γ = 90.053(2)° for Yb3Br2[AsO3][As2O5] with Z = 2. All three structures have the same building units with [REO8]13− and [REO4Br4]9− polyhedra as well as isolated ψ1-tetrahedral [AsO3]3− anions in common, with the exception that, in the latter two, ψ1-[AsO3]3− tetrahedra linked by a corner form a pyroanionic [As2O5]4− entity. A- and B-type differ in the stacking sequence of their 2∞{[(RE3)Ot4/1(Br1)v1/2(Br2)e3/3]6.5−} layers. While the former have an ABC sequence, the latter exhibit an AAA variant. In the triclinic structures, the (RE3)3+ sites are thinned out, while the As3+ sites are simultaneously enriched, resulting in the mentioned condensed units.

Ultrafast Synthesis of Nanoscale Metal Borides for Efficient Hydrogen Evolution.

Nanoscale metal borides, with exceptional physicochemical properties, have been attracted widespread attention. However, traditional synthesis methods of metal borides often lead to surface coking and large particle sizes. Herein, we have employed a flash Joule heating (FJH) technique to enable the ultrafast synthesis of metal boride nanomaterials. The synthesized materials encompass a wide range of diverse categories, including alkaline-earth metal borides (CaB6), transition metal borides (TiB2, VB2, CrB2, MoB, MoB2, MnB2, MnB4, FeB, CoB, NiB), noble-metal borides (RuB2, RuB1.1), and rare-earth metal borides (LaB6, CeB6). As an example, the RuB2 demonstrates highly desirable electrocatalytic performance for all-pH hydrogen evolution reaction (HER). Especially, under the acidic condition, it exhibits an overpotential as low as 15 mV at a current density of 10 mA cm-2, with a nearly 100% faradic efficiency. Additionally, in situ Raman spectra confirm that both Ru and B sites serve as active sites for the HER. Moreover, the stability of RuB2 can be further enhanced by optimizing the microenvironments of the anolyte composition (H+, K+). More importantly, the experimental and density functional theory (DFT) calculations reveal that the co-existence of H+ and K+ localized around the RuB2 plays a crucial role in further enhancing the stability.

The Missing Link in the Monogermanide Series: YbGe.

High-pressure, high-temperature synthesis at 12 GPa between 750 and 1000 °C for 30 to 300 min yields the last missing rare-earth metal monogermanide, YbGe. Powder and single-crystal X-ray diffraction measurements reveal that the compound crystallizes in a FeB-type structure (space group Pnma, a=7.901(2) Å, b=3.8981(9) Å, and c=5.873(2) Å). The results of the chemical bonding study, while supporting the presence of polyanionic Ge chains interacting with the surrounding Yb through multi-atomic polar bonds, suggest a transitional scenario between the monogermanides formed by alkaline-earth elements and those formed by trivalent rare-earth metals.

Main advances in the application of scorpionate-based catalytic systems for the preparation of sustainable polymers.

Scorpionate ligands have emerged as pivotal components in the field of coordination chemistry and catalysis since the seminal work by Trofimenko in the late 1960s. These species have demonstrated an extraordinarily rich tridentate coordination chemistry, enhancing the stability of metal complexes. In addition, they offer the possibility of modifying the chemical and electronical features as κ3-ligands, providing a wide variety of potential substrates with multiple donor atoms. Furthermore, this type of ligand has shown wide versatility in its coordination mode and can adopt different binding arrangements, expanding its potential as a universal ligand. This review provides a comprehensive overview of the main advances in exploring scorpionate complexes based on the tris(1H-pyrazol-1-yl)borate and bis(1H-pyrazol-1-yl)methane moieties, which have been recently reported as efficient catalysts for the synthesis of sustainable polymers. Specifically, this work focuses on the preparation of biorenewable polylactides (PLAs), other polyesters and polycarbonates (PCs), derived from cyclohexene carbonate, polylactide-co-polycarbonate copolymers and alternative sustainable polymeric materials. Thus, we have faced this challenge by selecting and classifying the most well-performed scorpionate catalyst system, including divalent (magnesium, calcium, zinc and iron) and other metals (rare-earth metals and zirconium), for each of the catalytic processes mentioned above. This review represents the first contribution that summarises and illustrates the current state of the art related to the use of scorpionate-based systems as efficient catalysts for the preparation of sustainable polymer materials. This account finally aims to guide future research towards the development of more eco-friendly catalytic processes in promoting sustainable polymers to achieve relevant commodities.

Recent advances of calcium(II) triflimide in organic synthesis

Environmentally benign calcium(II) triflimide has emerged as a sustainable substitute for transition-metal catalysts, rare-earth metals, and strong Brønsted acids in promoting organic synthesis, thereby attracting considerable attention. Recently, elegant methodologies...

Dual Doping with Nitrogen and Rare Earth Metals for Tailored Photoluminescence and Antimicrobial Properties in Hydrothermally Synthesized Carbon Dots

Dual Doping with Nitrogen and Rare Earth Metals for Tailored Photoluminescence and Antimicrobial Properties in Hydrothermally Synthesized Carbon Dots

Heterometallic trinuclear complexes of {η1-(Me3tacn)MoO3}2M(III) (M = Y, La, Sm, Eu, Nd, Yb) with rare earth metals based on the (Me3tacn)MoO3 metalloligand

Heterometallic trinuclear complexes of {η1-(Me3tacn)MoO3}2M(III) (M = Y, La, Sm, Eu, Nd, Yb) with rare earth metals based on the (Me3tacn)MoO3 metalloligand

Atomically dispersed rare earth dysprosium-nitrogen-carbon for boosting oxygen reduction reaction.

Transition metal-nitrogen-carbon (MNC) based on 3d metal atoms as promising non-precious metal catalysts have been extensively exploited for oxygen reduction reaction (ORR), but MNC with 4f rare earth metals have been largely ignored, most likely due to their large atomic radii that are difficult to coordinate with N dopants using conventional precursors. Herein, atomically dispersed dysprosium-nitrogen-carbon (DyNC) nanosheets were developed via the pyrolysis of anitrogen-containing chelate compound of 2, 4, 6-Tri (2-pyridyl) 1, 3, 5-triazine (TPTZ) ligand with Dy3+ under the assistance of molten NaCl. The as-synthesized DyNC features specific moieties of single Dy atom coordinated by N and O as active sites for ORR, displaying excellent performance. The half-wave potentials of 0.77V and 0.88V in acidic and alkaline media respectively are superior to those of iron-nitrogen-carbon (FeNC) synthesized using the same method. Meanwhile, a practical zinc-air battery verifies the ORR activity of DyNC with a maximum power output of 216 mW cm-2, which is even better than the commercial platinum on carbon catalyst (Pt/C) under the same loading.In addition, theoretical calculations verify that compared to the classic FeN4 moiety,the DyN4O1 exhibits a lower overpotential of 0.570V, demonstrating that it possesses more significant catalytic performance for ORR. This work provides the inspiration of developing non-precious metal electrocatalysts with atomic 4f rare earth metals for ORR.

Magnetic Domain Wall Energy Landscape Engineering in a Ferrimagnet.

Architectures based on a magnetic domain wall (DW) can store and process information at a high speed in a nonvolatile manner with ultra-low power consumption. Recently, transition-metal rare earth metal alloy-based ferrimagnets have attracted a considerable amount of attention for the ultrafast current-driven DW motion. However, the high-speed DW motion is subject to film inhomogeneity and device edge defects, causing challenges in controlling the DW motion and hindering practical application. In this work, we demonstrate a strategy for precisely engineering the DW energy landscape by locally modifying the compensation state in a ferrimagnet via ion irradiation by using the focused ion beam technique. A diode-like DW motion behavior is observed at the lateral junction interface, i.e., the boundary between irradiated and non-irradiated CoGd, enabling selective control over DW pinning and depinning at specific locations. Our work provides insight into the development of next-generation DW-based ferrimagnetic racetrack memory and logic devices.

Алгоритм извлечения металлов из растворов природного выщелачивания потерянных руд

The article discusses a solution to the problem of extracting metals from natural leaching solutions of the offgrade ores and their mill tailings to obtain ecological and economic efficiency, the relevance of which is steadily increasing. The methodology of studying the samples includes the methods of polarographic analysis, spectrometry, chromatography, titration and complexometry, etc. Sulfate-chloride waters were studied using industrial electrodialyzers with the solution circulation through brine chambers and without it with metal extraction by sorbents. Details are provided of the scheme of the electromembrane technology of combined metal extraction with the process regulation. The concept of natural leaching of the ores lost in the worked-out space by mine effluents has been clarified. An algorithm is proposed to purify the ore effluents with the production of a group of metals, including the rare earth metals, which combines the functions of metal deposition and purification of the mine effluents. The aggregate model combines the technological, environmental and economic aspects of mining within the framework of the natural and man-made systems. A conclusion is made that it is advisable to implement the recommendations of the study to solve the environmental problem and strengthen the raw material base by reducing the loss of valuable components. Implementation of the recommendations provided in the article contributes to the solution of the main tasks of mining, i.e. increasing a complete utilization of the subsoil resources and reducing the burden on the environment while ensuring the safety of operations.

Influence of centrifugal casting parameters on Al-Mg alloy castings microstructure and mechanical properties

The paper is dedicated to the process of obtaining hollow castings on a horizontal centrifugal casting machine. The influence of mold rotation speed and the melt pouring process mechanical properties of as-cast parts made of AlMg5, alloyed by small amount of transition and rare earth metals, is represented. Mold pouring processes and crystallization kinetics depend on mold rotational speeds 1100, 1500 and 2000 rpm were studied by using numerical modeling. The influence of the specified mold rotation speeds on the structure and mechanical properties of castings is shown. It is also determined that the installation of a foam ceramic filter in the pouring cup of a centrifugal casting machine ensures melt laminar flow when pouring it into a mold. It was determined that 1500 rpm is the most favorable rotating speed from the points of optimal hydrodynamic mold filling processes and casting crystallization kinetics. It was also shown that with the increase of a mold rotation speed from 1100 to 2000 rpm, the thickness of the defective inner layer decreases, the alloy structure refines, and the mechanical properties of as-cast detail increase the next way: at 1500 rpm (σ0.2–by 10%, σB − by 25%, δ − 3 times), at 2000 rpm (σ0.2–by 18%, σB − by 31%, δ − 4 times), compared to products obtained by steel mold gravity casting. Centrifugal casting technology ensures the mechanical properties of cast blanks even higher than those of deformed AlMg5 alloys, the values of which approach those of AlMg6 alloy products.

Optimization of Sidoarjo Mud Akaline Fusion Process Using Taguchi Method

Sidoarjo mud contains 48.3% silica which is considered as the biggest impurity when compared to the content of rare earth metals which are 0.3% Eu and 0.02% Yb. The hydrothermal process is used to bind silica as a form of silica extraction activity in the Sidoarjo mud so that the Rare Earth Elements are purified further because their uses are urgently needed. This process compares the alkalis in the form of Na2CO3 and K2CO3 which are basic salts which will then be compared to the most optimum conditions of the two alkalis. Each alkali will be processed under operating conditions following the Taguchi method which aims to minimize research and optimize research results. Based on the research results, it was found that K2CO3 provided better silica recovery than Na2CO3 under operating conditions with a K2CO3 concentration of 2 M, 1 hour soaking time, 700°C melting temperature and 3 hours melting time, giving 95.24% silica recovery. In addition, by using the Taguchi method it can be analyzed that the main factors affecting the melting of the alkali are the melting time, the concentration of the alkali, the temperature of the melting, and the immersion time.

Changes in the Kinetics of Hardening During Aging of Magnesium Alloy of the Mg – Y – Gd – Zr System Alloyed with Other Rare Earth Metals

Changes in the Kinetics of Hardening During Aging of Magnesium Alloy of the Mg – Y – Gd – Zr System Alloyed with Other Rare Earth Metals

Density Functional Theory Insights into Conduction Mechanisms in Perovskite-Type RCoO3 Nanofibers for Future Resistive Random-Access Memory Applications.

In the era of artificial intelligence and Internet of Things, data storage has an important impact on the future development direction of data analysis. Resistive random-access memory (RRAM) devices are the research hotspot in the era of artificial intelligence and Internet of Things. Perovskite-type rare-earth metal oxides are common functional materials and considered promising candidates for RRAM devices because their interesting electronic properties depend on the interaction between oxygen ions, transition metals, and rare-earth metals. LaCoO3, NdCoO3, and SmCoO3 are typical rare-earth cobaltates (RCoO3). These perovskite materials were fabricated by electrospinning and the calcination method. The aim of this study was to investigate the resistive switching effect in the RCoO3 structure. The oxygen vacancies in RCoO3 are helpful to form conductive filaments, which dominates the resistance transition mechanism of Pt/RCoO3/Pt. The electronic properties of RCoO3 were investigated, including the barrier height and the shape of the conductive filaments. This study confirmed the potential application of LaCoO3, NdCoO3, and SmCoO3 in memory storage devices.

On the prospects of identifying rare and rare earth metals in the black shale sequence of the Eastern segment of the Greater Caucasus

The expansion, updating, and comprehensive utilization of the mineral resource base for rare and rare-earth metals necessitate the search for and development of new deposits of non-traditional genetic types, including those localized within black shale formations. This study examines the distribution of rare and rare-earth elements (REE) in the black shale formation of the Eastern segment of the Greater Caucasus, where extensive research and exploratory drilling have led to the discovery of several deposits and occurrences of non-ferrous metals. The results of geochemical and mineralogical investigations reveal a high concentration of rare and rare-earth elements (REE) and other metals within the black shale formation. All lithological types of rocks constituting the black shale formation, as well as rocks from the near-deformation and hydrothermally metasomatized zones, were tested for this study. Comparative studies of the behavior of rare and rare-earth elements across various rock types indicated significant variations in their elemental spectrum and concentrations. Notably, elevated concentrations of rare-earth elements were observed in clay-rich rocks, attributed to the sorptive capacity of clay minerals. Analysis of the distribution of microelements in the rocks and main minerals of the black shale formation highlighted a considerable presence of rare, rare-earth, and other elements, with concentrations exceeding their Clarke values by several times. Distinct anomalous zones were identified for Au, Mo, Cs, La, Ce, Nd, Sm, and U, while anomalous zones were noted for Cd, Se, Hf, Yb, Lu, Eu, Tb, and Th. The geochemical characteristics related to the concentration of these elements were also determined. The findings indicate that the unique properties of graphitized clay shales and accessory minerals within the formation significantly influence the processes of concentration of rare and rare-earth elements, serving as sources of associated metals. This study further analyzes the geochemical and mineralogical characteristics of the black shale formation and delineates zones of mobilization and concentration for rare, rare-earth, and other elements.

Tin-Chelated Trisphosphineoxide Scorpionate Rare-Earth Porphyrinate Complexes: Synthesis and Photophysical Properties.

A series of seven-coordinated monoporphyrinate rare-earth(III) complexes featuring a novel tripodal tin-chelated trisphosphineoxide scorpionate ligand with the general formula [(TPP)Ln(PPh2O)3Sn] (Ln = Y, La, Dy, Er, Ho, Yb; TPP = 5,10,15,20-tetraphenylporphyrinate) were synthesized by reactions of the potassium tripodal scorpionate ligand [Sn(PPh2O)3K] with porphyrinate rare-earth metal chlorides [(TPP)LnCl(dme)] (Ln = Y, Dy, Er, Ho, Yb) or porphyrinate lanthanum borohydride [(TPP)LaBH4(thf)2]. The complexes were characterized by single-crystal X-ray diffraction, NMR spectroscopy, and ion mobility mass spectrometry. All complexes emit weak red TPP-based fluorescence, accompanied by near-infrared emission of Er, Ho (rather weak), and Yb (relatively intense with a quantum yield of 1% in dichloromethane solution) of the corresponding complexes. Despite the low intensity, the red fluorescence is characteristic (as referred to the parent free-base TPP) and can be used together with optical absorption for analytical evaluation. Similar photophysical properties can be expected for monoporphyrinate rare-earth metal complexes of other tripodal ligands with a similar binding to the (TPP)Ln moiety.

Preparation of dilute solutions of rare earth metal trichlorides by chlorination of their oxides in a molten NaCl-KCl equimolar mixture

The article is devoted to the study and thermodynamic justification of the method for obtaining dilute solutions of rare earth metal trichlorides by chlorination of their oxides in a molten equimolar mixture of NaCl – KCl. And the effectiveness of this method is demonstrated by the example of lanthanum (III) and neodymium (III) oxides. Gibbs free energy of the reactions of La2O3 and Nd2O3 chlorination by different chlorinating agents has been calculated. The interaction of lanthanum (III) and neodymium (III) oxides in the molten equimolar mixture NaCl – KCl depending on the chlorination time and the material of reaction vessel (beryllium oxide and glass-carbon) has been studied experimentally. The results of thermodynamic modelling of the chlorination reactions of La2O3 and Nd2O3 by gaseous chlorine in this salt melt are presented. In the case of using a molten equimolar mixture of NaCl – KCl, a significant shift of the Gibbs energy to the negative region is observed compared with chlorination without the use of a salt medium. The effectiveness of chlorine as a chlorinating agent in the melt is based on the fact that in liquid NaCl-KCl Ln3+ ions form complexes with very small activity coefficient. The removal of synthesized lanthanum trichloride from the chlorination reaction zone due to its solubility in a low-viscosity NaCl-KCl melt has a beneficial effect on the rate of its flow. It has been shown that the formation of rare earth metal trichlorides occurs through the formation of LaOCl and NdOCl oxychlorides. The advantages of the proposed method of chlorination of rare earth metal oxides (REM) in the synthesis of solutions of their trichlorides in molten salts are shown.

Synthesis of macrocyclic salen rare-earth complexes and their framework conversion regulated by coordination sphere engineering.

We now report a macrocyclic rare-earth complex whose frameworks have been regulated between a trimer and a tetramer by an external capping ligand. Coordination sphere engineering of the rare earth metals with flexible and variable coordination numbers (CN > 6) offers a unique way to control the self-assembled structures.

Research on Metal-based High-temperature Superconductors and BCS Mechanism

Recently, high-temperature superconductors have had a wide range of applications in fields such as electric power transportation, medical imaging and diagnostics, electronic devices, and quantum computing. Therefore, this paper reviews the properties and mechanisms of copper-oxide, iron-based, nickel-based and hydrogen-based high-temperature superconductors. The results show that optimizing the copper-oxygen layer structure and regulating the interlayer coupling are effective methods to improve the performance of copper oxide high-temperature superconductors. This method can enhance the superconducting current, thus improving their superconducting properties. For iron-based high-temperature superconductors, the superconducting transition temperature and energy gap can be enhanced by doping rare earth elements or transition metal elements, and adjusting the topology of the Fermi surface to change the internal electronic structure of the material. The double-layer structure of nickel-based high-temperature superconductors is investigated by using tensor networks and other methods, which significantly increase the Tc of the material and solve the problems of difficult preparation by detecting the impurity effect and vortex state of the material. For hydrogen-based superconductors, chemical pre-pressurization and doping with alkali metal elements are mainly used to synthesize ternary hydrogen-based superconductors and hydrogen-minor superconductors. This can significantly increase the transition temperature of superconducting materials and reduces the pressure required for their preparation. Therefore, this study can improve the superconducting properties of these high-temperature superconductors and extend their applications in the fields of electric power transportation, medical imaging and diagnostics, electronic devices and quantum computing.