Journal of Rare Earths最新文献

{"title":"Enhancement of weathered crust elution-deposited rare earth ores leaching process with PQ-10 addition","authors":"Aoyang Sha ,&nbsp;Huifang Yang ,&nbsp;Zhengyan He ,&nbsp;Zhigao Xu ,&nbsp;Chenjie Wu ,&nbsp;Ming Wu ,&nbsp;Ru'an Chi","doi":"10.1016/j.jre.2023.12.005","DOIUrl":"10.1016/j.jre.2023.12.005","url":null,"abstract":"<div><div>To solve the problems of the long development period, low mass transfer efficiency and high impurity content in the <em>in-situ</em> leaching process of weathered crust elution-deposited rare earth ores (WCE-DREO), cationic hydroxyethyl cellulose (PQ-10) was composited with conventional leaching agent ammonium sulfate ((NH₄)₂SO₄) to form a novel composite leaching agent. The effects of PQ-10 concentration, leaching temperature and leaching flow rate of the composite leaching agent on the leaching kinetics and mass transfer processes of rare earth (RE) and aluminum (Al) were investigated. Compared to the single leaching agent (NH₄)₂SO₄, the composite leaching agent (2 wt% (NH₄)₂SO₄+0.02 wt% PQ-10) can reduce the RE leaching equilibrium time from 465 to 130 min and increase the RE leaching efficiency and decrease the Al leaching efficiency. It also facilitates the leaching process of WCE-DREO by increasing the peak concentrations of RE and Al, reducing the theoretical tower plate height (HETP) and improving the leaching mass transfer efficiency. It is indicated that PQ-10 can promote the leaching of WCE-DREO. The leaching process of the composite leaching system conforms to the diffusion kinetic control model. When the PQ-10 concentration is in the range of 0.005 wt%<strong>–</strong>0.020 wt%, the reaction orders of RE and Al are 0.73 and 0.54, respectively, which shows a positive effect on the leaching velocity; when the PQ-10 concentration is in the range of 0.030 wt%<strong>–</strong>0.060 wt%, the reaction orders of RE and Al are <strong>–</strong>1.16 and <strong>–</strong>0.75, respectively, which show a negative effect on the leaching velocity. In the range of 10<strong>–</strong>50 °C, the apparent activation energies of RE and Al are 15.02 and 17.31 kJ/mol, respectively, and the higher the leaching temperature, the smaller the HETP and the higher the leaching velocity and mass transfer efficiency. The increase in leaching flow rate contributes to the increase in the longitudinal diffusion velocity of the leaching agent within WCE-DREO, causing a shorter time for RE and Al to reach leaching equilibrium. In addition, the flow rate and HETP are consistent with the Van Deemter equation. At a flow rate of 0.8 mL/min, HETP was minimized and the optimal mass transfer efficiencies is achieved for RE and Al.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 180-190"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138575206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetism and cryogenic magnetocaloric effect of triangular-lattice LnOF (Ln = Gd, Dy, Ho, and Er) compounds","authors":"Jianjian Gong ,&nbsp;Lu Tian ,&nbsp;Lei Zhang ,&nbsp;Zhaojun Mo ,&nbsp;Yuanpeng Wang ,&nbsp;Jun Shen","doi":"10.1016/j.jre.2023.10.005","DOIUrl":"10.1016/j.jre.2023.10.005","url":null,"abstract":"<div><div>Frustrated lanthanide oxides with dense magnetic lattice and suppressed ordering temperature have potential applications in cryogenic magnetic refrigeration. Herein, the crystal structure, magnetic properties, magnetic phase transition (MPT) together with magnetocaloric effect (MCE) of LnOF (Ln = Gd, Dy, Ho, and Er) compounds were investigated. Crystallographic study shows that these compounds crystallize in the centrosymmetric space group <span><math><mrow><mi>R</mi><mover><mn>3</mn><mo>¯</mo></mover><mi>m</mi></mrow></math></span> with an ideal triangular lattice. No long-range magnetic ordering is observed above 2 K for LnOF (Ln = Gd, Ho, and Er). However, DyOF compound undergoes an MPT from paramagnetic (PM) to antiferromagnetic (AFM) at the Néel temperature (<em>T</em>_N ≈ 4 K). Considerable reversible MCE is observed in these triangular-lattice compounds. Under the magnetic field change (<em>μ</em>₀Δ<em>H</em>) of 0–2 T, the maximum values of magnetic entropy change <span><math><mrow><mo>(</mo><mrow><mo>-</mo><mi>Δ</mi><msubsup><mi>S</mi><mtext>M</mtext><mtext>max</mtext></msubsup></mrow><mo>)</mo></mrow></math></span> of them are 6.1, 9.4, 12.7, and 14.1 J/(kg·K), respectively. Interestingly, the value of ErOF with Ising-like spin is 2.3 times that of GdOF, which provides an approach for exploring magnetic refrigerants with excellent low-field cryogenic magnetocaloric effect.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 98-104"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135706581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable and wideband high-performance rare earth-doped Ni-Mg-Cu-Zn nano ferrite-based meta-absorbers for C-band application","authors":"Majid Niaz Akhtar ,&nbsp;Magbool Alelyani ,&nbsp;Fatimah Mohammed A. Alzahrani ,&nbsp;Abdullah Almohammedi ,&nbsp;Sabih Qamar ,&nbsp;M.A. Baqir ,&nbsp;M. Irfan ,&nbsp;Muhammad Azhar Khan ,&nbsp;Kheir S. Albarkaty ,&nbsp;Z.A. Alrowaili ,&nbsp;M.S. Al-Buriahi","doi":"10.1016/j.jre.2023.12.007","DOIUrl":"10.1016/j.jre.2023.12.007","url":null,"abstract":"<div><div>Due to advanced technology, electromagnet interference and dissipation problems in the electronic and portable devices at GHz range are increasing daily. Magnetic absorbing materials with outstanding electromagnetic properties, wide bandwidth, and strong absorption are highly desirable. The present investigation deals with the preparation of Ni-Mg-Cu-Zn (NMCZ) substituted nano ferrites with composition of Ni_0.3Mg_0.2Cu_0.3Zn_0.2X_0.02Fe_1.98O₄ (X = Nd, Ho, Pr, Gd, Yb). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), a vibratory sample magnetometer (VSM), and a Vector network analyzer (VNA) were used to investigate these rare earth-doped nanocrystalline ferrites' features. XRD reveals the single spinel phase structure in all Ni-Mg-Cu-Zn ferrites. FTIR spectroscopy shows the presence of tetrahedral and octahedral bands of spinel ferrites. FESEM images reveal the lowest agglomeration for the Ho-doped NMCZ nano-spinel ferrites sample. TEM images show the hexagon shapes of the Yb- and Nd-doped NMCZ ferrites. Pr-doped NMCZ ferrites show more coercivity than other rare earth metals substituted NMCZ nanocrystalline ferrites. VSM analysis was used to calculate the magnetic features like initial permeability, magnetic anisotropy constant, remanence, coercivity, and magnetic moment. High-frequency switching field distributions (SFD) analyses were also investigated. Magnetodielectric characteristics such as losses, permittivity, modulus, <em>Q</em>, ac conductivity, and impedance of the Nd-, Ho-, Pr-, Gd-, Yb-doped Ni-Mg-Cu-Zn ferrites were evaluated. The minimum reflection loss (–57.3 dB) is found at 1.4 GHz for Pr-doped Ni-Mg-Cu-Zn ferrite absorber. However, the reflection loss (RL) of –53.9 dB at 2.9 GHz is observed for Ho-doped Ni-Mg-Cu-Zn ferrite absorber. Soft magnetization, low coercivity, outstanding magnetodielectric, and absorption properties of the Nd-, Ho-, Pr-, Gd- and Yb-doped Ni-Mg-Cu-Zn ferrites are suitable candidates for absorption in telecommunication, defense, and technological industries.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 124-132"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139022449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoluminescence upgradation of La2MgTiO6:2%Dy3+ perovskite with monovalent (Li+), divalent (Ba2+, Sr2+) and trivalent (Bi3+, Sm3+) cation sensitization","authors":"V.P. Veena ,&nbsp;K. Arun ,&nbsp;C.K. Shilpa ,&nbsp;S.V. Jasira ,&nbsp;K.M. Nissamudeen","doi":"10.1016/j.jre.2023.12.013","DOIUrl":"10.1016/j.jre.2023.12.013","url":null,"abstract":"<div><div>Nano phosphors of 2% Dy³⁺ (wt%) doped La₂MgTiO₆ and monovalent/divalent/trivalent co-doped La_1.98Dy_0.02MgTiO₆:<em>x</em>%A^<em>y</em>+ (A^<em>y</em>+: Li⁺, Ba²⁺, Sr²⁺, Bi³⁺, and Sm³⁺; 0 ≤ <em>x</em> ≤ 2 wt%) were synthesized by combustion method. From the XRD data, it is deduced that an increase in the valency of co-dopant increases the crystallinity of the double perovskite orthorhombic nanocrystal structure. With an increase in co-dopant size, an elevation in optical bandgap is visible with the highest bandgap of 3.835 eV for Bi³⁺. The photo-absorption is monotonically broadened for Sr²⁺, Sm³⁺, and Li⁺ around 200–450 nm. Under 351 nm, Dy³⁺ triggered lattice shows major characteristic emission peaks at 480 nm (⁴F_9/2 → ⁶H_15/2), 574 nm (⁴F_9/2 → ⁶H_13/2), and 670 nm (⁴F_9/2 → ⁶H_11/2), leading to near white light emission with CIE coordinates (0.341, 0.376). Upon co-doping, the PL intensity is significantly increased with maximum emission for trivalent Sm³⁺, followed by divalent Sr²⁺ and monovalent Li ⁺ respectively. With increasing excitation wavelength, Sr²⁺ shows a dominated output and it is found that divalent Sr²⁺ is a potential co-dopant that could enhance luminescence intensity up to 6 times with a Sr²⁺ → Dy³⁺ energy transfer efficiency of 86%. It is specified that the CIE coordinates of Li⁺ co-doped samples show ideal white emission with color coordinates (0.333, 0.336). The concluding outcomes signify the noblest rare earth Sm³⁺ co-doping and thus Sm³⁺ → Dy³⁺ energy transfer mechanism is discussed in detail.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 47-56"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139067211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic effects of constituents in rare earth-based composites: Enhanced structural, electrical and magnetic properties for water splitting applications","authors":"Chitralekha ,&nbsp;S. Shankar ,&nbsp;A.P. Singh","doi":"10.1016/j.jre.2024.01.018","DOIUrl":"10.1016/j.jre.2024.01.018","url":null,"abstract":"<div><div>Rare earth-based Bi_0.85La_0.15FeO₃ (BLFO) and NdMnO₃ (NMO) particles were synthesised using the solid-state route, and their roles affecting structural, electrical, magnetic properties along with hydroelectric application in different concentrations i.e., (1–<em>x</em>)BLFO:<em>x</em>NMO (where <em>x</em> = 0, 0.10, 0.20, 0.30 and 1.0) ceramics composites were investigated. X-ray diffraction analyses confirm the pure-phase formation of BLFO:NMO composites, featuring micrometer-scale crystallite sizes. Fourier transform infrared (FT-IR) spectra of BLFO:NMO composites reveal peak shifts with rising NMO content, indicating composite formation. These composites exhibit robust Maxwell–Wagner polarization and a pronounced composition-dependent behavior. The addition of NMO to BLFO results in a rise in dielectric permittivity at lower frequencies, confirming relaxor behavior and indicating success in achieving the transition temperature. Impedance spectroscopy facilitates a clearer understanding of how charge carriers contribute to these composites and the impact of grain/grain boundaries. The saturation magnetization maximum value (i.e., 0.807 emu/g) was attained in 0.7BLFO-0.3NMO. The coercivity decreases with the addition of NMO in BLFO. The results suggest the composite's enhanced suitability for microelectronics and hydropower cells, showing improved hydroelectric cell performance with increased NMO in BLFO, highlighting a notable ion diffusion mechanism.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 105-114"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139690266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective recovery of rare earth elements by smelting of magnets","authors":"Venkata Lakshmi Borra ,&nbsp;Prasanta Jana ,&nbsp;P.P. Sahoo ,&nbsp;Prakash Venkatesan ,&nbsp;Mehmet Ali Recai Önal ,&nbsp;Chenna Rao Borra","doi":"10.1016/j.jre.2024.02.019","DOIUrl":"10.1016/j.jre.2024.02.019","url":null,"abstract":"<div><div>Rare earth elements (REEs) play a crucial role in many technologies from daily appliances in cell phones to more advanced wind turbines and electric cars. Permanent magnets account for a quarter of total global REEs production and have high recycling value. In this study, smelting process was used to selectively oxidize REEs in the permanent magnets by adding Fe₂O₃. This separates REEs into a slag phase from an iron-rich metallic phase. B₂O₃ was also added to the system as a flux to lower the slag melting temperature. This minimizes REEs loss to the metallic phase and allows a more efficient phase separation. The effect of flux and oxidizing agent addition was investigated on both regular and cerium-rich NdFeB (NdCeFeB) magnets. At 1350 °C and for 1 h, the slag phase was successfully separated from the metallic phase with the addition of 0.8 stoichiometric amount of Fe₂O₃ and 40 wt% of B₂O₃. Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDX) analysis reveals that REEs in the magnet do not migrate to the metal phase while the REE-rich slag phase contains almost no iron. After the selective removal of iron into the metallic phase, REEs are recovered from the slag phase through an acid leaching process allowing &gt;99% of REEs recovery. Boron in the magnet can also be recovered as useful boric acid by evaporation and crystallisation technique. The proposed process in this study is reagent and energy-efficient with almost complete valorisation of both NdCeFeB and NdFeB magnets.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 209-217"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140125266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding amorphous PrOx-based N-doped carbon catalyst as an efficient electrocatalyst for oxygen reduction reaction","authors":"Xiao Man,&nbsp;Ying Chang,&nbsp;Shaohong Guo,&nbsp;Meilin Jia,&nbsp;Jingchun Jia","doi":"10.1016/j.jre.2024.04.005","DOIUrl":"10.1016/j.jre.2024.04.005","url":null,"abstract":"<div><div>The development of an efficacious and easily prepared nonprecious metal electrocatalyst is crucial for the oxygen reduction reaction (ORR). This work used a dual template method to prepare the amorphous rare earth-based catalyst PrO_<em>x</em>-NC, and optimized the calcination temperature and proportion. The PrO_<em>x</em>-NC-900 catalyst has high durability and activity and exhibits superior ORR performance in alkaline electrolytes with an onset potential (<em>E</em>₀) of 0.96 V and a half-wave potential (<em>E</em>_1/2) of 0.85 V. The research results indicate that the ORR performance of rare earth oxide composite carbon catalysts can be improved by adjusting oxygen vacancies (O_v). In addition, high specific surface area, N rich defect carbon, increased oxygen vacancies, and the synergistic effect of oxygen vacancies and N-doped carbon interfacial layer play a significant part in the enhancement of ORR. The performance of the zinc air battery assembled with PrO_<em>x</em>-NC-900 is significantly improved, and rare earth oxides and carbon frameworks originating from metal organic frameworks (MOFs) contribute to the oxygen electrocatalyst and electron transfer rate of the zinc air battery. This catalyst provides promising information for the development of rare earth metal oxide nanostructures as potential candidate materials for ORR in alkaline media.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 73-80"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140769067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creation of an oxygen-enriched environment during synthesis as an effective way to improve luminescent properties of Y2O3:Eu3+","authors":"Aleksandr A. Nashivochnikov ,&nbsp;Anton I. Kostyukov ,&nbsp;Mariana I. Rakhmanova ,&nbsp;Lidiya S. Kibis ,&nbsp;Svetlana V. Cherepanova ,&nbsp;Evgenii A. Suprun","doi":"10.1016/j.jre.2023.12.008","DOIUrl":"10.1016/j.jre.2023.12.008","url":null,"abstract":"<div><div>The growing demand for luminescent nanomaterials intended for various applications increases the necessity to develop and improve approaches to the creation of highly efficient nanosized phosphors. In current study, an approach to enhancing the efficiency of red luminescence of monoclinic Y₂O₃:Eu³⁺ with the particle size of ∼20 nm by creating the oxygen-enriched environment during the gas-phase synthesis was developed. To investigate the effect of oxygen amount during the synthesis on characteristics of the phosphor, a series of nanostructured Y₂O₃:Eu³⁺ with the addition of 0–40 vol% O₂ to the main buffer gas Ar was synthesized by laser vaporization. It is shown that the amount of added O₂ exerts virtually no effect on the phase composition and particle size, but significantly improves the luminescent characteristics of Y₂O₃:Eu³⁺. Thus, the addition of 30 vol% O₂ leads to virtually a 20-fold growth in the photoluminescence (PL) intensity caused by ⁵D₀→⁷F_0–4 transitions in Eu³⁺ and an increase in the absolute PL quantum yield from 3% to 53% (<em>λ</em>_ex = 395 nm) compared to the sample synthesized without O₂. The addition of oxygen also improves the emission color coordinates from (0.571, 0.320) to (0.630, 0.322) due to the removal of a considerable fraction of oxygen vacancies. The synthesized nanopowders are shown to be highly stable: upon storage under ambient conditions for two years. Quantum yield (QY) of the samples decreases by less than 2%. It is expected that the key features underlying the proposed approach will be useful for various methods used to synthesize oxide nanophosphors.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 21-29"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138741646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leaching of rare earths and aluminum in weathered crust elution-deposited rare earth ore using magnesium sulfate: Effect of aluminum content in leaching agent solution","authors":"Depeng Liu ,&nbsp;Weiqiang Yin ,&nbsp;Zheng Li ,&nbsp;Jiaxin Pan ,&nbsp;Longsheng Zhao ,&nbsp;Chunmei Wang","doi":"10.1016/j.jre.2023.11.012","DOIUrl":"10.1016/j.jre.2023.11.012","url":null,"abstract":"<div><div>Aluminum is the main impurity of the weathered crust elution-deposited rare earth ore (WCED-REO). Efficient leaching of rare earths and low leaching of aluminum are of great importance for the leaching of the WCED-REO. The effects of pH, MgSO₄ concentration and Al³⁺ concentration of the leaching agent solution on the column leaching behaviors of WCED-REO using magnesium sulfate were investigated. Experimental data show that controlling the MgSO₄ concentration to 0.15 mol/L, pH of the leaching agent solution to 2, the leaching amount of aluminum from the rare earth ore gradually decreases with the increase of Al³⁺ concentration in the leaching agent solution, indicating that Al³⁺ in the leaching agent solution may act as leaching agent to participate in the ion exchange of RE³⁺, but the leaching amounts of rare earths change insignificantly as the Al³⁺ concentration is increased. Increasing the MgSO₄ concentration is beneficial to the leaching of aluminum, and when the Al³⁺ concentration is 0.04 mol/L (Al accumulation), the amount of Al³⁺ leached from the rare earth ore increased gradually with increasing the MgSO₄ concentration. The pH of the leaching agent solution has a significant influence on the leaching of aluminum in the rare earth ore, and the leaching amount of aluminum from the rare earth ore increases gradually with decreasing the pH. When the Al³⁺ concentration is 0.04 mol/L (Al accumulation) and the pH of the leaching agent solution is above 2.0, the aluminum in the leaching agent solution can be back-adsorbed onto the rare earth ore, and the amount of the back-adsorbed Al³⁺ increases with increasing the pH of the leaching agent solution. The injection rate of the leaching agent solution has slight effect on the leaching behavior of rare earths and aluminum. In summary, leaching of Al³⁺ and consumption of MgSO₄ can be reduced by regulating the accumulation of aluminum, MgSO₄ concentration and pH.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 191-198"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138540085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A molecular dynamics simulation route towards Eu-doped multi-component transparent spectral conversion glass-ceramics","authors":"Xiuxia Xu ,&nbsp;Chenhao Wang ,&nbsp;Di Wang ,&nbsp;Wenyan Zheng ,&nbsp;Zhiyu Liu ,&nbsp;Jincheng Du ,&nbsp;Xusheng Qiao ,&nbsp;Xianping Fan ,&nbsp;Zhiyu Wang ,&nbsp;Guodong Qian","doi":"10.1016/j.jre.2024.01.016","DOIUrl":"10.1016/j.jre.2024.01.016","url":null,"abstract":"<div><div>Eu²⁺ doped fluorosilicate glass-ceramics containing BaF₂ nanocrystals have high potential as spectral conversion materials for organic solar cells. However, it is difficult to realize the efficient design of BaF₂:Eu²⁺ doped fluorosilicate glass and to vividly observe the glass microstructure in experiment through traditional trial-and-error glass preparation method. BaF₂:Eu²⁺ doped fluorosilicate glass-ceramics with high transparency, and high photoluminescence (PL) performance were predicted, designed and prepared via molecular dynamics (MD) simulation method. By MD simulation prediction, self-organized nanocrystallization was realized to inhibit the abnormal growth of nanocrystals due to [AlO₄] tetrahedra formed in the fluoride-oxide interface. The introduction of NaF reduces the effective phonon energy of the glass because Na⁺ will prompt Al³⁺ to migrate from the fluoride phase to the silicate phase and interface. The local environment of Eu²⁺ is optimized by predicting the doping concentration of EuF₃ and 2 mol% EuF₃ is the best concentration in this work. Glass-ceramics sample GC2Eu as spectral conversion layer was successfully applied on organic solar cells to obtain more available visible phonons with a high photoelectric conversion efficiency (PCE). This work confirms the guidance of molecular dynamics simulation methods for fluorosilicate glasses design.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 146-152"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139668008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}