PHILOSOPHICAL MAGAZINE
·
2022
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IF 1.948
Ailian Zhu,Yupeng Xie,Keyou Shi,Min Chen,Jiawei Li,Yimin Zhou,Gaiyuan Chen,Yong Liu
Coal fly ash (hereinafter CFA) was employed to rapidly immobilise Nd-contaminated soil with the addition of TiO2 via microwave sintering technology. The effect of TiO2 doping on the phase composition, microstructure, elemental distribution, density, and chemical durability of the solidified samples was systemically investigated. The results indicated that the Nd element can be incorporated in the matrix with oxyapatite and pyrochlore as TiO2 content increased at 1200°C. Moreover, the sintered sample with the high bulk density and low open porosity was fabricated at a TiO2-doping amount of 7 wt.%. Meanwhile, the as-prepared samples doping with TiO2 exhibited excellent chemical durability. Especially, the sintered sample doping with 3 wt.% TiO2 had the lowest leaching rate (7.97×10−6 g·m−2·d−1 at 28 d). Our investigation reflects that CFA is suitable for Nd-contaminated soil immobilisation via microwave sintering technology and the introduction of TiO2 is conducive to the improvement of densification and chemical durability.
研究领域:
材料科学
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环境科学
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高影响因子
Advanced Energy and Sustainability Research
·
2023
·Vol. 4
·期 9
·2300023
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IF 5.8
Shuai Zhang,Mingzi Sun,Leilei Yin,Siyuan Wang,Bolong Huang,Yaping Du,Chun-Hua Yan
The oxygen evolution reaction (OER) is critical for renewable energy conversion and storage devices. However, the rational design of electrocatalysts with suitably high efficiency and stability in strongly acidic electrolytes remains a major challenge. Herein, a solid-phase synthesis strategy is developed for the preparation of Ir-Ln (Ln = La, Ce, Pr, Nd) alloy nanoparticles with uniform particle size on carbon supports as superior acidic OER catalysts. Tailoring by the rare earth (RE) elements, Ir 2 Pr achieves a maximum mass activity of 2.10 A mg −1 Ir at 300 mV overpotential and stability over 200 h at 10 mA cm −2 in 0.5 m H 2 SO 4 , which is 9.5 and 20 times higher to pure Ir nanoparticles. Furthermore, Ir 2 Pr alloy nanoparticles exhibit excellent durability in strongly acidic electrolytes. Theoretical calculations have confirmed that the OER performances are strongly related to the RE elements in the alloy, where the d-band centers show a consistent trend with the overpotential. Moreover, the highest electroactivity of Ir 2 Pr is attributed to the improved electron transfer by 4 f orbitals and the suitable binding strength of intermediates. Herein, a fundamental understanding of the lanthanide–electrochemical performance relationship is provided and will also inspire the rational design of efficient nanoscale RE alloy electrocatalysts.
研究领域:
材料科学
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电化学
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能源转换与存储
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Hongxing Chen,Renquan Wang,Jun Li,Chang Liu,Xiaojiao Yang,Ying Liu
The combination of high coercivity and resistivity is a strong requirement for permanent magnets to resist thermal demagnetization under complex operating conditions. However, this still remains a challenge for conventional strategies, which always sacrifice the maximum energy product as the coercivity or resistivity increases. In this work, we report a unique strategy of introducing only 0.1 wt% of insulating nano-diamonds (NDs) into the hot-deformed Nd-Fe-B magnets to significantly and simultaneously improve both magnetic properties ( H ci , B r , (BH) max and H k / H cj ) and resistivity. In particular, the coercivity increased by 60% from 746 to 1193 kA/m. Further microstructure observations indicate that this exceptional effect stems from NDs can effectively inhibit the formation of coarse grains and optimize the distribution of Nd-rich phases, ensuring a strong pinning effect to enhance hard magnetic performance. Meanwhile, the presence of additional grain boundaries and NDs can also lead to higher resistivity by preventing the movement of free electrons. Our work provides a distinctive strategy for interface modification with excellent comprehensive performance in permanent magnets.
研究领域:
材料科学
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磁学
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高影响因子
CERAMICS INTERNATIONAL
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2023
·
IF 5.2
Jun-Wei Huang,Xiao-Feng Dong,Xiao-An Lv,Xiao-Na Ren,Chang-Chun Ge
The Si 3 N 4 ceramics with ternary ZrN–AlN–Re 2 O 3 (Re=Yb, Y, Nd, Ce, La) and ZrN–AlN system as sintering additives were prepared by hot-pressed sintering with vacuum environment at 1750°C-30min–30MPa. Subsequently, the effect of the ternary additives system with 2 wt% Re 2 O 3 on phase transformation, grain boundary phases, microstructure, and mechanical properties of the Si 3 N 4 ceramics were investigated firstly. All samples achieved the high β-Si 3 N 4 phases transformation (≥98.86%), while the grain boundary phases Re x Zr 1-x O (4-x)/2 and Yb 2 Si 2 O 7 were detected in the sintered Si 3 N 4 ceramics with Re 2 O 3 additives. Additionally, compared with Si 3 N 4 ceramic not contain Re 2 O 3 additives, the Si 3 N 4 ceramics added Re 2 O 3 additives presented the textured microstructure with more elongated rodlike β-Si 3 N 4 grains based on the XRD and SEM results. Consequently, the sample S-Ce with added CeO 2 additive shows the highest relative density of 99.85% and optimal fracture toughness of 8.75 ± 0.36 MPa m 1/2 . The sample S–Nd with added Nd 2 O 3 additive presented a highest bending strength of 1061.78 ± 41.76 MPa. Sample S–Yb with added Yb 2 O 3 additive presented the maximum Vickers hardness of 16.35 ± 0.07 GPa. The results of this study can provide a helpful reference for the preparation of high-performance Si 3 N 4 ceramics.
研究领域:
材料科学
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陶瓷工程
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高影响因子
CRYSTAL GROWTH & DESIGN
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2025
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IF 3.4
Yun Lv,Yanhong Wang,Yaling Dou,Ang Li,Jinkui Tang,Olga S. Volkova,Alexander N. Vasiliev,Hongcheng Lu
We report the synthesis and magnetic properties of three rare-earth magnetic compounds RE2O2CN2 (RE = Nd, Dy, Gd) with a frustrated triangular spin–lattice, as well as their thermal stability and Fourier transform infrared (FTIR) spectroscopy. The magnetic susceptibility results show paramagnetic behavior with no long-range order (LRO) down to 2 K in Nd2O2CN2 and Dy2O2CN2 due to spin frustration, which are further confirmed by the specific heat measurements, despite the large Curie–Weiss temperature for strong intralayer interaction through the RE–O–RE pathway (RE = Nd, Dy). While Gd2O2CN2 with a large spin exhibits LRO at 2.7 K, which should be caused by the non-negligible interlayer interactions. The field-dependent magnetization curves show a linear increase up to 7 T for Nd2O2CN2 and Gd2O2CN2, which are far from their saturation. While the magnetization of Dy2O2CN2 increases linearly below 3 T, then slowly increases to saturation, and the magnetization value is 6.62 μB at 7 T. Our work provides promising magnetic triangular lattice systems to further investigate frustration and quantum magnetism in rare-earth magnetic systems.
研究领域:
凝聚态物理
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材料化学
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磁性与磁性材料
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量子材料
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2018
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IF 3.779
Yaozu Guo,Junhua You,Wenli Pei,Yingdong Qu,Dong Zhao,Zhengwen Yang
This paper reports a novel chemical method to synthesize Nd-Fe-B magnetic nanoparticles . The fabrication mechanism of the particles have been studied through understanding formation of the corresponding intermediate phases as well as their microstructures after annealing and reduction-diffusion processes as function of the (C 2 H 5 ) 3 NBH 3 content. Nd-Fe-B intermediate phases were composed of small Fe 3 O 4 particles and Nd and Fe microcrystals encapsulated with nitriles . Fe 3 O 4 was reduced by BH 3 − into α-Fe as the (C 2 H 5 ) 3 NBH 3 content increased. After annealing, Nd-Fe-B oxide particles gradually agglomerated as the (C 2 H 5 ) 3 NBH 3 content increased, which affected the particle sizes after the reduction-diffusion step. Mixture of Nd 2 Fe 14 B and H 5 Nd 2 was obtained from precursors synthesized with 1.5 and 2.5 mmol of (C 2 H 5 ) 3 NBH 3 . Magnetic properties of these mixtures demonstrated soft magnetic phase characteristics. Relatively pure Nd 2 Fe 14 B nanoparticles with a coercivity of 5.09 kOe and magnetic energy product (BH max ) of 2.862 MGOe were obtained when (C 2 H 5 ) 3 NBH 3 initial content was 3.5 mmol. Exchange coupling nanoparticles of Nd 2 Fe 14 B, Fe 3 B and Fe 2 B were obtained with the coercivity of 3.787 kOe and (BH) max equal to 4.871 MGOe at (C 2 H 5 ) 3 NBH 3 content of 4.5 mmol.
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高影响因子
CRYSTENGCOMM
·
2022
·Vol. 25
·期 1
·95-107
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IF 3.756
Lei Wang,Xudong Liu,Jinsheng Li,Mu Zhang,Xiaoguo Bi,Zhixin Ma,Jialin Chen,Xudong Sun
High-performance dielectric materials are essential components of electronic devices. In this work, RE-doped SrTiO3 (RE = La, Nd, Yb) single crystals with excellent dielectric properties were prepared by the Verneuil method. For La-STO and Nd-STO, the RE ions are substituted for Sr2+ only, and the excellent dielectric properties are mainly caused by defect dipoles associated with oxygen vacancies including and defect dipole clusters. For Yb-STO, Yb3+ partially replaces Ti4+, forming an additional defect dipole , resulting in the best dielectric properties (ε′ = 3.6 × 104, tan δ = 0.0036 under 1 kHz). In addition, N2 atmosphere treatment promotes the production of oxygen vacancies and Ti3+ and the formation of more defect dipoles, thus further optimizing the dielectric properties of Yb-STO (ε′ = 4.9 × 104, tan δ = 0.004 under 1 kHz). This work suggests that the dielectric properties of RE-doped SrTiO3 materials are closely related to oxygen vacancies, and the simultaneous substitution of Sr2+ and Ti4+ should enable obtaining dielectric properties superior to those of the substitution of Sr2+ only. The present work provides a clearer understanding of the origin of SrTiO3 dielectric properties, which is of great significance to the development of SrTiO3-based dielectric materials.
研究领域:
材料科学
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凝聚态物理
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电子器件
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DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
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2026
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IF 7.9
Han Yu,Ying Wang,Zhen Shi,Chenxi Fang,Hang Zeng,Junting Sun,Vilko Mandić,Xuefeng Zhang
Although superhydrophobic coatings have been widely employed for corrosion protection due to their low surface energy, their low surface energy characteristic also results in weak interfacial adhesion and the influence of interfacial adhesion on the overall anti-corrosion performance remains poorly understood. Herein, we explored the corrosion resistance of superhydrophobic coatings on sintered Nd-Fe-B magnets from the perspective of work of adhesion (Wₐ), which represented the interfacial stability and bonding strength. By precisely controlling the PDA shell thickness and the degree of hydrophobization, the work of adhesion can be regulated correspondingly. The results revealed that the overall anti-corrosion performance of superhydrophobic coatings was directly proportional to the work of adhesion. At an optimized Wₐ of 49.44 mN·m -1 , the coated magnet exhibited a low corrosion current density of 1.09 × 10 −8 A/cm 2 , which was three orders of magnitude lower than that of 3.27 × 10 −5 A/cm 2 for bare Nd-Fe-B magnet. Moreover, outstanding protection durability was also demonstrated in both acidic and alkaline environments with robust interfacial contact. In contrast, weak adhesion induced the formation of interfacial gaps, which served as preferred penetration pathways for the corrosive medium. This study evidenced the importance of interfacial structural integrity, revealing the critical role of adhesion layer design in enabling robust and durable anti-corrosion performance of superhydrophobic coatings.
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高影响因子
ELECTROCHIMICA ACTA
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2026
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IF 5.8
Kaung Khant Kyaw,Tao Jiang,Heng Cao,Zhaoyang Leng,Hajra Baig,Waris Ghani,Youqi Zhu,Chuanbao Cao,Meishuai Zou
Lattice contraction increases defect oxygen species and modifies surface transition-metal redox states. • HEP-Nd-0.3 achieves a bifunctional potential gap ΔE = 0.77 V with OER overpotential of 290 mV and ORR half-wave potential of 0.75 V. • Zn-air battery delivers 115 mW cm⁻² peak power density and stable operation for over 340 h. • A-site lattice modulation alone enhances intrinsic OER/ORR activity without aliovalent doping. Rechargeable zinc–air batteries require bifunctional air-cathode catalysts capable of efficiently catalyzing both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, La 1-x Nd x (Cr 0.2 Mn 0.2 Fe 0.2 Co 0.2 Ni 0.2 ) O 3 (x = 0, 0.1, 0.2, and 0.3) high-entropy perovskites (HEP) were synthesized to examine the influence of isovalent Nd³⁺ substitution at the A site on bifunctional oxygen electrocatalysis. Replacement of La³⁺ with smaller Nd³⁺ preserves the nominal A-site charge while inducing lattice contraction and modifying the surface chemical environment of the multication perovskite. Among the investigated compositions, HEP-Nd-0.3 exhibits the best bifunctional activity, delivering an OER overpotential of 290 mV at 10 mA cm −2 , an ORR half-wave potential of 0.75 V versus RHE, and a bifunctional potential gap of 0.77 V. When used as the air-cathode catalyst in a rechargeable zinc–air battery, HEP-Nd-0.3 achieves a peak power density of 115 mW cm −2 and stable charge–discharge operation for >340 h. The enhanced performance is associated with Nd-content-dependent variations in lattice structure, surface oxygen chemistry, electrochemically accessible surface area, and charge-transfer characteristics. These results identify isovalent rare-earth A-site substitution as a practical strategy for tuning high-entropy perovskite oxygen electrocatalysts. Download: Download high-res image (313KB) Download: Download full-size image
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Zhongyan Luo,Jukka Kuva,Jan Luyten,Risto Koivula,Małgorzata Szlachta,Hongli Bao,Junhua Xu
The increasing demand for Co, Nd, and Dy, particularly in neodymium iron boron (NdFeB) magnets, has heightened concerns over their supply risks. Developing efficient, environmentally friendly methods to recover Co, Nd, and Dy from spent NdFeB magnets is therefore critical. This study presents the synthesis of two types of crystalline zirconium phosphate (ZrP) encapsulated in polyacrylonitrile (PAN) composite beads. The structure, morphology, and chemical properties were analyzed using X-ray diffraction (XRD), thermogravimetry (TG), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray computed tomography (XCT), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and 31 P nuclear magnetic resonance (NMR). The intercalation of dimethylformamide (DMF) enlarged the interlayer spacing of α-ZrP and γ-ZrP, thereby enhancing their ion exchange properties. Batch sorption experiments revealed that α-ZrP/PAN outperformed γ-ZrP/PAN in both sorption and separation efficiency. α-ZrP/PAN beads exhibited high selectivity for Nd 3 + and Dy 3 + , with minimal Co 2 + sorption (8.57 %). Stepwise elution studies on α-ZrP/PAN demonstrated the obtained metal purities to be ∼100 wt% for Co, 64.1 wt% for Nd, and 96.5 wt% for Dy. Sorbent regeneration was investigated over ten sorption–desorption cycles, which revealed that α-ZrP/PAN retained 72.72 % of its sorption capacity, demonstrating excellent reusability and stability, while γ-ZrP/PAN’s capacity declined to 68.95 % after five cycles. The ion-exchange reaction accompanied by shrinking of the interlayer space was illustrated by combining the batch sorption experiments, column operations, and analyses from XRD, FT-IR, and X-ray photoelectron spectroscopy (XPS). Overall, α-ZrP/PAN shows promise for Co, Nd, and Dy separation from NdFeB magnets, although further optimization of sorbents and elution agents is necessary.
研究领域:
材料科学
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环境工程
·
化学工程
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高影响因子
Journal of Materials Chemistry B
·
2018
·Vol. 6
·期 6
·966-978
·
IF 4.776
Pei Wang,Pan Xiong,Jing Liu,Shuang Gao,Tingfei Xi,Yan Cheng
Magnesium (Mg) alloys have been intensively investigated as potential absorbable coronary stent materials as their use avoids risks such as late inflammation and restenosis generated by permanent metallic implants. Besides that, clinical trials on coronary stents fabricated from Mg alloys have made great progress recently. However, the over-rapid corrosion rate, magnesium corrosion-induced thrombosis formation and delayed endothelium regeneration continue to be problematic for coronary artery stent therapy. In this study, silk fibroin blended with heparin and GREDVY (Gly-Arg-Glu-Asp-Val-Tyr) peptide was immobilized on a HF-pretreated MgZnYNd alloy surface via a polydopamine layer to improve its corrosion resistance, blood compatibility and endothelialization. Standard electrochemical measurements along with the long-term immersion results indicated that the functionalized MgZnYNd alloy had preferable anti-corrosion abilities compared with the bare MgZnYNd alloy. The modified surface exhibited outstanding hemocompatibility with reduced platelet adhesion, hemolysis rate and prolonged blood coagulation time. Human umbilical vein endothelial cell (HUVEC) and vascular smooth muscle cell (VSMC) co-culture results revealed more attached HUVECs on the functionalized samples than on the MgZnYNd alloy surfaces. The excellent corrosion retardation, hemocompatibility and re-endothelialization of the multi-functional coating indicate a promising method in the field of biodegradable magnesium-based implantable cardiovascular stents.
研究领域:
生物医学工程
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材料科学
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心血管疾病研究
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DOI
PubMed
高影响因子
Advances in Applied Ceramics
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2018
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IF 1.092
Kuibao Zhang,Dan Yin,Xirui Lu,Haibin Zhang
In this study, the zirconolite-rich composite was rapidly synthesised from self-propagating high-temperature synthesis plus quick pressing using MoO3 as the oxidant and Ti as the reductant. As a surrogate of trivalent actinides, Nd was introduced to substitute the Ca site of zirconolite and Al was employed as the charge compensator to replace the Ti site (nominally Ca1−xNdxZrTi2−xAlxO7). The phase composition and Nd occupancy were analysed after Nd2O3 addition. Nd-bearing zirconolite was produced as the major ceramic phase. Nd mostly substitutes the Ca sites of zirconolite, which results in waste loading higher than 8.6 wt-% Nd. The aqueous durability of Nd–Al codoped sample (with 15 at.-% Nd substitutes the Ca site of zirconolite) was evaluated at 90°C as well. The 42 days normalised leaching rates of Mo, Ca and Nd were measured to be 3.70, 1.90 × 10−2 and 3.46 × 10−4 g m−2 d−1.
研究领域:
材料科学
·
核化学与放射化学
·
无机化学
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高影响因子
危险品化学品经营许可证（带存储）