Journal of Rare Earths最新文献

{"title":"In-situ synthesizing nanoscale (Zr,Ti)B2 at intergranular regions of NdCeFeB magnets with enhanced corrosion resistance","authors":"Xuegeng Wang ,&nbsp;Bo Song ,&nbsp;Xiaolian Liu ,&nbsp;Shutai Zhou ,&nbsp;Song Fu ,&nbsp;Kai Xu ,&nbsp;Xinxin Li ,&nbsp;Junjie Ni","doi":"10.1016/j.jre.2025.01.016","DOIUrl":"10.1016/j.jre.2025.01.016","url":null,"abstract":"<div><div>An idea hits us that <em>in-situ</em> synthesizing ceramic phase at intergranular regions of RE-Fe-B alloys should be beneficial to the performance of the materials against corrosion, and in this work a new nanoscale (Zr,Ti)B₂ with space and point groups of <em>P</em>6<em>/mmm</em> and <em>Fmmm</em>, respectively, was successfully synthesized in NdCeFeB sintered magnets. The hcp-structured (Zr,Ti)B₂ phases are present in a stripe-like shape. Some of (Zr,Ti)B₂ are developed at interfaces, and the others exist inside grain boundary phase. They co-exist with REFe₂ and RE-rich phases at intergranular regions. When proximity to RE₂Fe₁₄B grains, their orientation relationships obey <span><math><msub><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow><mrow><msub><mi>Nd</mi><mn>2</mn></msub><msub><mi>Fe</mi><mn>14</mn></msub><mi>B</mi></mrow></msub><mo>∥</mo><msub><mrow><mo>[</mo><mn>1</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>0</mn><mo>]</mo></mrow><mrow><msub><mrow><mo>(</mo><mi>Zr</mi><mo>,</mo><mi>Ti</mi><mo>)</mo><mi>B</mi></mrow><mn>2</mn></msub></mrow></msub></math></span>. The formation of (Zr,Ti)B₂ generates significant local compressive stress, being 8.48 GPa, and plenty of reliefs are developed inside the RE₂Fe₁₄B grains. The <em>in-situ</em> formed (Zr,Ti)B₂ modifies the magnet microstructure, lessens the favorable sites for absorption reaction, narrows reaction channels, and reduces the potential difference between intergranular phase and main phase. Such favorable factors greatly enhance the corrosion resistance with an <em>i</em>_corr decrement by 70% in comparison to the unmodified magnet. These new discoveries are thought to be able to provide an insight into the method of potentially improving properties of magnets.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 5","pages":"Pages 989-996"},"PeriodicalIF":5.2,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873565","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":"CeO2@MnO2 with strong Ce-Mn interaction activating PDS to promote in situ degradation of adsorbed tetracycline","authors":"Jinhui Zhang ,&nbsp;Jiawei Sun ,&nbsp;Xinfeng Zhu ,&nbsp;Jingquan Liu ,&nbsp;Linlin Chang ,&nbsp;Guofeng Li ,&nbsp;Rongfu Peng ,&nbsp;Junning Wang ,&nbsp;Libin Jiang ,&nbsp;Kai Wang ,&nbsp;Shiqiang Yin ,&nbsp;Xueping Liu ,&nbsp;Chaohai Wang","doi":"10.1016/j.jre.2025.01.006","DOIUrl":"10.1016/j.jre.2025.01.006","url":null,"abstract":"<div><div>A series of CeO₂@MnO₂ composites was prepared by deposition–precipitation methods. These materials were used to activate sodium persulfate (PDS) for the oxidation of tetracycline. It is found that the composites, especially the CeO₂@MnO₂-1:4 composites, exhibit better tetracycline removal rates than the pure components. X-ray diffraction (XRD), Raman and scanning electron microscopy (SEM) analyses all indicate that the composite has been successfully prepared with high purity and high crystalline. The XPS analysis shows that the strong interaction between the components promotes the electron transfer. Additionally, the kinetic rate constants of CeO₂@MnO₂-1:4 after 60 min are 3.8 and 12.7 times higher than pure CeO₂ and MnO₂, respectively. CeO₂@MnO₂-1:4 composite also exhibits excellent catalytic activity for individual and hybrid pollutants. The effects of wastewater matrix, pH, circulation and ion strength on the degradation of tetracycline were investigated. It is found that CeO₂@MnO₂-1:4 composite has good practical application prospects. CeO₂@MnO₂ composites with synergistic adsorption catalysis can activate PDS and peroxymonosulfate (PMS) for efficient organic catalytic oxidation. This paper provides the theoretical basis and data support for the practical application of the CeO₂@MnO₂ composite materials.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 3","pages":"Pages 490-499"},"PeriodicalIF":5.2,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479153","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":"Persistent scintillators for X-ray repetitive imaging with stable energy traps","authors":"Yuan Wang ,&nbsp;Peng Zhang ,&nbsp;Xu Tian ,&nbsp;Daiyuan Liu ,&nbsp;Jian Zhang ,&nbsp;Zhichao Liu ,&nbsp;Xiuxia Yang ,&nbsp;Jie Yu ,&nbsp;Jianxiong Shao ,&nbsp;Xuhui Xu","doi":"10.1016/j.jre.2025.01.002","DOIUrl":"10.1016/j.jre.2025.01.002","url":null,"abstract":"<div><div>Scintillator is a key material for the development of X-ray detectors, which has a promising application in medical imaging, security inspection and industrial non-injury detection. The majority of scintillators currently used in imaging are real-time imaging scintillators, which can cause ionization radiation damage to biological subjects or detection equipment during the imaging process and require complex, highly sensitive detection systems. Therefore, exploring stable, environmentally friendly scintillator materials that can achieve delayed imaging is of significance in the field of imaging. Herein, we developed an X-ray time-lapse imaging scintillator, Sr₂Al₆O₁₁:Dy³⁺ phosphor, which generates stable traps by X-ray irradiation, thus endowing it with excellent persistent luminescence and information storage properties (&gt;42 d). Moreover, traps constructed by X-ray can be repeatedly refilled (&gt;40 times) under UV light and carriers are released in the form of mechanical or thermal excitation when refilling is complete. By constructing the traps in the phosphor during X-ray excitation and using it for repetitive imaging, the detection limit is 74.78 nGy/s, and the spatial imaging resolution is as high as 16 lp/mm. This discovery provides a new idea for the development of time-delayed X-ray scintillator.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 6","pages":"Pages 1161-1168"},"PeriodicalIF":5.2,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169870","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":"Bluish-green emission of novel BaAl2Ge2O8:Eu2+ phosphors under near-ultraviolet excitation","authors":"Sk. Khaja Hussain ,&nbsp;Jae Su Yu","doi":"10.1016/j.jre.2023.11.016","DOIUrl":"10.1016/j.jre.2023.11.016","url":null,"abstract":"<div><div>A new class of phosphor samples, denoted as Ba_{1–<em>x</em>}Al₂Ge₂O₈:<em>x</em>Eu²⁺ (BAGO:<em>x</em>Eu²⁺) was synthesized using a Pechini-type sol–gel technique and subsequent thermal reduction in CO atmosphere. The morphology and structural characteristics of both the BAGO host lattice and the Eu²⁺ ions activated BAGO phosphors were investigated through field-emission scanning electron microscopy and X-ray diffractometry analyses, respectively. The BAGO host lattice has micro-sized particles and the Rietveld refinement reveals the presence of a monoclinic crystal phase, characterized by the space group <em>I</em>2/<em>c</em> (No. 15). Introducing Eu²⁺ ions into Ba²⁺ sites under CO condition reduces the particle size, switching from microscale to nanoscale. Within the near-ultraviolet spectrum (353 nm), the BAGO:<em>x</em>Eu²⁺ phosphors exhibit a broadband bluish-green photoluminescence (PL) emission characterized by a peak band at 492 nm. This phenomenon is attributed to the 4f⁶5d¹ → 4f⁷ electronic transition. The BAGO:0.02Eu²⁺ phosphor shows the strongest bluish-green PL emission, and a comprehensive description of the concentration quenching mechanism between Eu²⁺ ions is revealed. Additionally, the thermal stability of the optimized BAGO:0.02Eu²⁺ phosphor was investigated, and its activation energy was estimated. Therefore, the synthesized bluish-green BAGO:0.02Eu²⁺ phosphor holds the promise of being a novel and potential candidate for utilization in white light-emitting diode applications.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 30-38"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138540099","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":"Rare earth elements: Sector allocations and supply chain considerations","authors":"Mpila Makiesse Nkiawete,&nbsp;Randy Lee Vander Wal","doi":"10.1016/j.jre.2024.01.020","DOIUrl":"10.1016/j.jre.2024.01.020","url":null,"abstract":"<div><div>This article addresses the question of how the global and U.S. market sector allocations for rare earth elements compare. Accordingly, this article reports rare earth oxide (REO) market sector allocations, resolved by elemental profile for 2020 and reciprocally REO consumption resolved by end market use. Differences are calculated relative to 2008 and presented as percentages and as absolute tonnage. These differences encompass both changes in relative sector demand and growth rate. Historical trends, global and U.S. for REO usage by sector are calculated for the period of 2018–2022. End market sector demands, as percentages are presented, referenced to United States Geological Survey (USGS) values from 2008. Attention is given to permanent magnets and associated elements given the growing renewable generation and vehicle electrification. The criticality of Nd and Dy are considered given that they are the foundation of NdFeB permanent magnets, prominent in electric vehicle traction motors and direct drive wind turbine generators. Economic activity associated with REE market sectors is presented. Notably usage does not reflect economic value. A prime example are catalysts versus magnets. Last, vast reserves of light and heavy REEs exist in coal and coal-byproducts with potential high impact upon critical REEs and associated economics.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 1-8"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139690161","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":"Mössbauer, optical and structural properties of Fe3+ ion in borate glass","authors":"Essam A. Elkelany ,&nbsp;Hesham Y. Amin ,&nbsp;A. Samir ,&nbsp;M.M. EL-Hady ,&nbsp;H.H. El-Bahnasawy ,&nbsp;Moukhtar A. Hassan","doi":"10.1016/j.jre.2024.02.021","DOIUrl":"10.1016/j.jre.2024.02.021","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Lanthanum-bearing iron lithium borate glass is a quaternary system for oxide glasses and was prepared via the melt-quenching method. The present article correlates the structure, optical, ligand field and Mössbauer data on iron lithium borate glass containing &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;La&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. The density was measured, while the molar volume was calculated. Other physical parameters are well-described. With increasing the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mtext&gt;La&lt;/mtext&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; content within the glass network, infrared spectra analysis reveals structural modifications such as the increase in &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mtext&gt;BO&lt;/mtext&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; units and the decline in both &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mtext&gt;BO&lt;/mtext&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; units and NBO bonds content. Furthermore, optical absorption spectra were measured. The absorption spectra disclose a plethora of electronic transitions that are related to &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;Fe&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; in tetrahedral and octahedral sites, however, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;Fe&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; phase is not observed in optical spectra, but it has a clear signature in Mössbauer spectra. Besides, the glass absorption edges undergo a clear blue shift, reflecting an increased band gap energy (1.96–2.28 eV). The decline in NBO bonds justifies this trend. Bewitchingly, the values of crystal field splitting are increased, while the values of Racah parameters are decreased. This trend is justified by the decline in NBO bonds and increases electron localization around Fe cations. Mössbauer spectra confirm the existence of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;Fe&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; in tetrahedral and octahedral sites, while &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;Fe&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; exists in only a tetrahedral state. With increasing &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mtext&gt;La&lt;/mtext&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; content, the isomer shift of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;Fe&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; in tetrahedral sites changes to be 0.312–0.329 mm/s, while the isomer shift of octahedral &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;Fe&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; is 0.424–0.456 mm/s. These findings coincide with optical data. While the isomer shift of tetrahedral &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mtext&gt;Fe&lt;/mtext&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; is 0.902–0.911 mm/s. Our results of structural, optical and ligand field associated with Mössbauer spectra open more vistas toward the utility of these samples in the optics rea","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 162-170"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140124980","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":"Insight into physical properties of lutetium-based double half-Heusler alloys LuXCo2Bi2 (X = V, Nb and Ta)","authors":"Saber Saad Essaoud ,&nbsp;Said Al Azar ,&nbsp;Ahmad A. Mousa ,&nbsp;Anas Y. Al-Reyahi ,&nbsp;Nabil Al Aqtash ,&nbsp;Mohammed Elamin Ketfi","doi":"10.1016/j.jre.2023.11.011","DOIUrl":"10.1016/j.jre.2023.11.011","url":null,"abstract":"<div><div>Based on the density functional theory, the double half-Heusler alloys LuXCo₂Bi₂ (X = V, Nb, and Ta) were studied to predict their structural, thermodynamic, thermoelectric, and optical characteristics. All the considered alloys are thermodynamically stable and have semiconductor behavior with indirect band gaps of 0.62, 0.75, and 0.8 eV for LuVCo₂Bi₂, LuNbCo₂Bi₂, and LuTaCo₂Bi₂, respectively. The investigated compounds exhibit semiconducting behavior with energy gaps below 0.8 eV. The impact of heat and pressure on thermodynamic coefficients was evaluated, and the influence of charge carriers on the temperature-dependent properties was studied using the semi-classical Boltzmann model. The studied compounds were characterized by their low lattice thermal conductivity at room temperature and low thermal expansion coefficient. These alloys exhibit substantial absorption coefficients in the ultraviolet (UV) light region, high optical conductivity, and high reflectivity in the visible light region, making them highly appealing materials for applications in the energy and electronics sectors.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 199-208"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138540087","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":"Effect of divalent cations (Co2+ and Ni2+) on microstructure, physical properties and application of NdFeO3","authors":"M.M. Arman","doi":"10.1016/j.jre.2023.12.003","DOIUrl":"10.1016/j.jre.2023.12.003","url":null,"abstract":"<div><div>The nanocrystalline samples Nd_{1–<em>x</em>}M_<em>x</em>FeO₃ (<em>x</em> = 0.0 and 0.1; M: Co²⁺ and Ni²⁺) were prepared using the citrate combustion method. The X-ray diffraction (XRD) pattern confirmed that the nanoparticles were synthesized in an orthorhombic structure. The particle size of Nd_{1–<em>x</em>}M_<em>x</em>FeO₃ is in the range of 29–59 nm. The selected area electron diffraction (SAED) indicates the samples were prepared in a polycrystalline nature. The samples Nd_{1–<em>x</em>}M_<em>x</em>FeO₃ (<em>x</em> = 0.0 and 0.1; M: Co²⁺ and Ni²⁺) have antiferromagnetic behavior. The Fe³⁺ spins are aligned antiparallel, forming the antiferromagnetic (AFM) properties, which are affected by many factors such as the bond angle between the Fe³⁺ (Fe³⁺–O^2––Fe³⁺) and the Dzyaloshinskii-Moriya (D-M) interaction. The doping of Co²⁺ and Ni²⁺ ions in NdFeO₃ enhances the magnetic properties of the NdFeO₃. The saturation magnetization (<em>M</em>_s) of Nd_0.90Co_0.10FeO₃ increases 1.8 times more than that of NdFeO₃. The exchange bias field (<em>H</em>_EX) of the Co-doped sample is two times greater than that of NdFeO₃. The magnetic anisotropy constant (<em>K</em>) of the 10% Co-doped sample increases by 11 factors compared to that of NdFeO₃. The Tauc plot illustrates that the samples have a direct optical transition. The divalent cation substitution (Co²⁺ and Ni²⁺) decreases the optical band gap of NdFeO₃, leading to the recommendation of using the samples Nd_0.90Co_0.10FeO₃ and Nd_0.90Ni_0.10FeO₃ in photocatalysis of dye degradation from water. The removal efficiencies of Cr⁶⁺ at pH = 6 are 88.06%, 85.54%, and 85.52% for the samples NdFeO₃, Nd_0.90Co_0.10FeO₃, and Nd_0.90Ni_0.10FeO₃, respectively. The Freundlich isotherm mode is the best-fit model for NdFeO₃ to adsorb Cr⁶⁺ ions from aqueous solutions.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 89-97"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138554144","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":"Influence of rare earth doping on hydrogen absorption properties of Zr7V5Fe alloy","authors":"Shuang Yang ,&nbsp;Zifeng Luo ,&nbsp;Guo Yang ,&nbsp;Lijun Lv ,&nbsp;Linhua Xu ,&nbsp;Haiyan Leng ,&nbsp;Xingbo Han ,&nbsp;Jianhui Zhu ,&nbsp;Wei Liu ,&nbsp;Pengfei Zhu ,&nbsp;Jing Xu","doi":"10.1016/j.jre.2024.01.006","DOIUrl":"10.1016/j.jre.2024.01.006","url":null,"abstract":"<div><div>As a representative of non-evaporative getter, Zr–V–Fe has gained widespread attention due to its advantages including low activation temperatures and rapid hydrogen absorption rates. In this study, we investigated the impact of La and Ce doping on the thermodynamic, kinetic, and activation properties of Zr₇V₅Fe alloy. X-ray diffraction analysis shows that rare earth doping causes a decrease in the cell volume of both the ZrV₂ and <em>α</em>-Zr phases of Zr₇V₅Fe alloy, which results in an increase in the plateau pressure of the alloys. The kinetic curves illustrate that rare earth doping leads to a coarse <em>α</em>-Zr phases and a larger particle size after activation, resulting in a decrease in the hydrogen absorption kinetic properties. As for the activation process, the rare earth doped alloys exhibit excellent activation with shorter incubation periods. X-ray photoelectron spectroscopy investigations reveal that Zr and V are initially in a highly oxidized state. As the heating temperature increases, they undergo a transition from oxidation state to metal state. The content of metal Zr in rare earth doped alloys is higher than that in undoped alloys at 250 °C, primarily due to rare earth elements' affinity for oxygen.</div></div>","PeriodicalId":16940,"journal":{"name":"Journal of Rare Earths","volume":"43 1","pages":"Pages 218-226"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139581593","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}