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Energy & Environmental materials 2024年第3期7卷 186-193页

作者： Xiaojun Zeng Qingqing Zhang Chulong Jin Hui Huang Yanfeng Gao Advanced Ceramic materials research institute School of Materials Science and EngineeringJingdezhen Ceramic University Singapore institute of Technology School of materials Science and Engineering Shanghai University

Transition metal phosphides with metallic properties are a promising candidate for electrocatalytic water oxidation,and developing highly active and stable metal phosphide-based oxygen evolution reaction catalysts is still ***,we present a facile ion exchange and phosphating processes to transform intestine-like CoNiPx@P,N-C into lotus pod-like CoNiFePx@P,N-C heterostructure in which numerous P,N-codoped carboncoated CoNiFePxnanoparticles tightly anchors on the 2D carbon ***,the as-prepared CoNiFePx@P,N-C enables a core-shell structure,high specific surface area,and hierarchical pore structure,which present abundant heterointerfaces and fully exposed active ***,the incorporation of Fe can also induce electron transfer in CoNiPx@P,IM-C,thereby promoting the oxygen evolution ***,CoNiFePx@P,IM-C delivers a low overpotential of 278 mV （vs RHE） at a current density of10 mA cm-1and inherits excellent long-term stability with no observable current density decay after 30 h of chronoamperometry *** work not only highlights heteroatom induction to tune the electronic structure but also provides a facile approach for developing advanced and stable oxygen evolution reaction electrocatalysts with abundant heterointerfaces.

关键词： electronic transfer Fe exchange multi-metal phosphides OER electrocatalysts structural evolution

Thermal stability improvement and microstructure optimization of high cobalt content Nd-Fe-B magnets via terbium grain boundary diffusion

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Journal of Rare Earths 2024年第8期42卷 1531-1538,I0004页

作者： Jiyuan Xu Ruiyang Meng Jing Liu Jiateng Zhang Rui Han Yikun Fang Shengzhi Dong Wei Li Division of Functional materials research Central Iron and Steel Research InstituteBeijing100081China

The substitution of Fe by Co in the 2:14:1 phase is an effective method to increase the Curie temperature and enhance the thermal stability of the Nd-Fe-B ***,the accumulation of Co ele ment at the grain boundaries(GBs) changes the GBs from nonmagnetic to ferromagnetic and causes the thinlayer GBs to become rare,In this paper,the method of diffusing Tb element was chosen to improve the microstructure and temperature stability of high-Co *** original sintered Nd_(28.5)Dy_(3)-CO_(x)e_(bal)M_(0.6)B_(i)(x=0,6 wt%,12 wt%;M = Cu,Al,Zr) magnets with different Co contents were diffused with Tb by grain boundary diffusion(GBD).After GBD,high-Co magnets exhibit more continuously distributed thin-layer GBs,and their thermal stability is significantly *** high-Co magnets(x=6 wt%),the absolute value of the temperature coefficient of coercivity decreases from 0.603%/K to0.508%/K in the temperature range of 293-413 K,that of remanence decreases from 0.099%/K to 0.091%/K,and the coercivity increases from 18.44 to 25.04 *** electron microscopy(TEM)characterization reveals that there are both the 1:2 phase and the amorphous phase in the high-Co magnet before and after GBD,EDS elemental analysis shows that Tb element is more likely to preferentially replace the rare earth elements in the 2:14:1 main phase than in the 1:2 phase and the amorphous *** concentration of Tb at the edge of the main phase is much higher than that in the 1:2phase and amorphous phase,which is beneficial to the improvement of the *** preferential replacement of Tb elements at the edge of the 2:14:1 phase and thin-layer GBs with a more continuous distribution are synergistically responsible for improving the thermal stability of high-Co *** study indicates that GBD is an effective method to improve the microstructure and thermal stability of high-Co magnets.

关键词： Nd-Fe-B magnets Coercivity Grain boundary diffusion Thermal stability Micro structure Rare earths

Pr-Tb synergistic strengthening on coercivity of Nd-Ce-Fe-B magnets grain boundary diffused with Pr-Tb-Al-Ga alloys

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Journal of Rare Earths 2024年第9期42卷 1704-1709,I0003页

作者： Ruifang Song Hang Zhao Haibo Feng institute of Functional materials Central Iron&Steel Research InstituteBeijing100081China

Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) *** effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and elements distribution of GBDed magnets was *** Pr is used to substitute for 75% Tb in diffusion source,Tb consumption per unit coercivity improvement of GBDed magnet reduces by 77%,compared with the Tb_(80)Al_(10)Ga_(10) diffused *** element diffuses into magnets and then forms Tb-rich shell with high magneto-crystalline anisotropy field surrounding main phase grains,resulting in substantial coercivity *** with low melting point diffuses deeply along liquid grain boundary phase during GBD *** can eliminate some sharp defects of main phase grains and make grain boundaries smooth,which provides diffusion channels for further diffusion of Tb ***,there are more diffusion channels for Tb and less Tb enriched at surface region,making Tb diffuse more deeply and improving Tb utilization *** method significantly improves the coercivity,and realizes the green,efficient and high-quality utilization of heavy rare earth(HRE)elements.

关键词： Grain boundary diffusion Rare earths Microstructure Synergistic strengthening

Mechanism of reduction-diffusion reaction in Sm-Fe binary system at low temperature using molten salts

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Journal of Rare Earths 2024年第10期42卷 1889-1894页

作者： Jungryang Kim Shusuke Okada Kenta Takagi Kimihiro Ozaki Innovative Functional materials research institute National Institute of Advanced Industrial Science and Technology (AIST)

In this study,the mechanism of the reduction-diffusion reaction in a Sm-Fe binary system at low temperature was studied to investigate the possibility of synthesis of a Fe-rich TbCu7-type SmFex（x>9）by the low-temperature diffusion-reduction（LTRD） process using LiCl-KCl eutectic molten ***,the Sm-Fe phase transformation depending on the Sm-Fe composition,the LTRD temperature,and time was investigated,and it is found that the obtained metastable phase is only TbCu7-type SmFe～8.5,which is not a Fe-rich *** Fe content does not change even after an expended LTRD process,and the metastable TbCu7-type SmFe～8.5tends to transform to the stable *** addition,it is found that the Sm-Fe phase starts to synthesize from the Sm-rich phase in the order of SmFe2,SmFe3,and SmFe8.5as the LTRD temperature increases（when the time was 10 h） or the LTRD time increases（when the temperature was 550℃）.Core-shell-like particles are observed in the case of a short LTRD time,and the core and the shell are Fe and the Sm-rich Sm-Fe phase,respectively,indicating that the Sm-rich phase begins to produce on the surface of the Fe *** is difficult to synthesize a Fe-rich TbCu7-type SmFex（x>9） phase with the Sm-Fe binary system,suggesting that a different approach,such as addition of other elements,will be necessary.

关键词： Low-temperature synthesis Molten salts Rare earths Reduction-diffusion process Sm–Fe compounds Synthesis mechanism

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in underdoped Bi2Sr2CaCu2O8+δ

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National Science Review 2024年第5期11卷 142-152页

作者： Shiyuan Wang Yijun Yu Jinxiang Hao Keyi Liang Bingke Xiang Jinjiang Zhu Yishi Lin Yinping Pan Genda Gu Kenji Watanabe Takashi Taniguchi Yang Qi Yuanbo Zhang Yihua Wang State Key Laboratory of Surface Physics and Department of Physics Fudan University Condensed Matter Physics and materials Science Department Brookhaven National Laboratory research Center for Functional materials National Institute for Materials Science International Center for materials Nanoarchitectonics National Institute for Materials Science Shanghai research Center for Quantum Sciences

Superconducting phase transitions in two dimensions lie beyond the description of the Ginzburg-Landau symmetry-breaking paradigm for three-dimensional *** are Berezinskii-KosterlitzThouless（BKT） transitions of paired-electron condensate driven by the unbinding of topological excitations,*** recently discovered monolayers of layered high-transition-temperature（TC）cuprate superconductor Bi2Sr2CaCu2O8+δ（Bi2212） meant that this 2D superconductor promised to be ideal for the study of unconventional *** inhomogeneity posed challenges for distinguishing BKT physics from charge correlations in this ***,we utilize the phase sensitivity of scanning superconducting quantum interference device microscopy susceptometry to image the local magnetic response of underdoped Bi2212 from the monolayer to the bulk throughout its phase *** monolayer segregates into domains with independent phases at elevated temperatures below *** a single domain,we find that the susceptibility oscillates with flux between diamagnetism and paramagnetism in a Fraunhofer-like pattern up to *** finite modulation period,as well as the broadening of the peaks when approaching Tc from below,suggests well-defined vortices that are increasingly screened by the dissociation of vortex-antivortex plasma through a BKT *** the multilayers,the susceptibility oscillation differs in a small temperature regime below TC,consistent with a dimensional crossover led by interlayer *** as strong evidence for BKT transition in the bulk,we observe a sharp jump in phase stiffness and paramagnetism at small fields just below *** results unify the superconducting phase transitions from the monolayer to the bulk underdoped Bi2212,and can be collectively referred to as the BKT transition with interlayer coupling.

关键词： cuprate superconductor monolayer Berezinskii-Kosterlitz-Thouless transition scanning SQUID paramagnetic Meissner effect

On-Chip Micro Temperature Controllers Based on Freestanding Thermoelectric Nano Films for Low-Power Electronics

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Nano-Micro Letters 2024年第7期16卷 98-108页

作者： Qun Jin Tianxiao Guo Nicolas Perez Nianjun Yang Xin Jiang Kornelius Nielsch Heiko Reith institute for Metallic materials Leibniz Institute for Solid State and Materials Research01069 DresdenGermany institute of materials Engineering University of Siegen57076 SiegenGermany institute of Applied Physics Technical University of Dresden01069 DresdenGermany institute of materials Science Technical University of Dresden01069 DresdenGermany

Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern ***,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely ***,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane *** tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are *** proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.

关键词： Temperature control Low-power electronics On-chip micro temperature controller Freestanding thermoelectric nano films Temperature-sensitive components

Microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents during heat treatments

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Rare Metals 2024年第4期43卷 1786-1792页

作者： Yuan-Feng Xie Xing-Cheng Xie Zhong-Wu Li Rui-Jun Cao Zhong-Kun Lin Qing Li Chen-Guang Lin Powder Metallurgy and Special materials research Department General Research Institute for Nonferrous MetalsBeijing100088China

The effects of cryogenic treatment(CT)and tempering-cryogenic treatment(TCT)on the microstructure and properties of coarse-grained WC-10Co cemented carbides with different carbon contents were *** binder phase,WC mean grain sizes,W solubility in the binder,relative magnetic s aturation,densities,hardness,wear resistance and second phase precipitation of cemented carbides with different heat treatments were *** results show that there are significant changes of microstructure and properties in the samples with CT and TCT,especially due to the precipitation of metastable nanoparticles W_(x)Co_(y)C_(z) in the binder during the heat treatments of CT and *** the simultaneous combination of microstructure and nanoparticle-reinforced binder,a dramatically improved combination of hardness and wear resistance of the samples after TCT has been achieved.

关键词： Cryogenic treatment Tempering Coarsegrained cemented carbide Carbon content Nanoparticlereinforced binder

Influence of erbium addition on microstructure and performances of AlSi10Mg alloy prepared by selective laser melting

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Journal of Rare Earths 2024年第10期42卷 1988-1994页

作者： Bin Chen Fuzhu Wang Shiming Ren Peng Xia Zhipeng Wang Jianfei Hao Zhiping Chen Runxia Li Hongxiang Jiang research institute of Interdisciplinary Science & School of materials Science and Engineering Dongguan University of Technology College of materials Science and Engineering Shenzhen University Shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of Sciences School of materials Science and Engineering University of Science and Technology of China

The effect of rare earth addition on the microstructure and mechanical performances of as-cast and wrought Al alloys has been attracting increasing attention *** earth addition has great potential in modifying the structure and improving the properties of ***,there are currently few reports about the effect of rare earth addition on the microstructure and performances of Al alloys prepared via selective laser ***,AlSi10Mg alloys were manufactured using selective laser melting,and the effect of Er addition was *** results indicate that Er addition leads toα-Al refinement and modifies the minority Si *** formation of the Al3Er phase induced by Er addition enhances the stren gth of the *** of the Si phase also increases *** strategy can help improve the mechanical performance of alum inum alloys prepared via selective laser melting.

关键词： Aluminum alloy Er Microstructure Rare earths Selective laser melting Tensile performance

High-performance anisotropic SmCo-based magnet with novel microstructure

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Journal of Rare Earths 2024年第8期42卷 1539-1545,I0005页

作者： Yingchang Li Zicao Xing Nengjun Yu Zesong Ren Minxiang Pan Qiong Wu Hongliang Ge Minggang Zhu Wei Li College of materials and Chemistry China jiliang UniversityHangzhou 310018China Division of Functional materials research Central Iron and Steel Research InstituteBeijing 100081China

A novel micro structure of magnetically anisotropic Sm Co-based magnet with high-performance is *** magnet consists of SmCo_(7)-H(TbCu_(7)-hexagonal type),Sm_(2)Co_(17)-H(Th_(2)Ni_(17)-hexagonal type)and SmCo_(3)-R(SmCo_(3)-rhombohedral type)*** maximum magnetic energy product of the magnet is 231.69 kj/m^(3),and the intrinsic coercivity is 1005.47 kA/*** outstanding intrinsic coercivity temperature coefficient(β)of-0.125%/K between 298 and 773 K is obtained,which is very close to theβof commercial high-temperature Sm_(2)Co_(17)-based sintered *** initial magnetization curve indicates that the coercivity mechanism is controlled by a domain wall pinning *** SmCo_(3)-R lamellar phase may be a potential pinning center or self-pinning *** microstructure of the magnet is different from that of any previous SmCo-based *** findings provide a new idea for preparing high-performance SmCo-based permanent magnets.

关键词： Rare earths Permanent magnet Composite magnet Melt-spinning Microstructure

Comprehensive tensile properties improved by deep cryogenic treatment prior to aging in friction-stir-welded 2198 Al–Li alloy

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Rare Metals 2024年第10期43卷 5403-5409页

作者： Jian-Qiu Sun Yue Ma Chong Gao Hong-Yun Luo School of materials Science and Engineering Beihang University Chinalco research institute of Science and Technology

In order to improve the comprehensive mechanical properties,deep cryogenic treatment （DCT）prior to aging was carried out on friction-stir-welded（FSW） 2198 Al-Li alloy;afterward,the microstructure and tensile properties were characterized by means of optical microscopy （OM）,transmission electron microscopy（TEM） and tensile *** results show that FSW 2198 alloy through DCT prior to aging （DAT） possesses superior tensile properties than conventional aging treatment （AT）The microstructural analysis reveals that DAT alloy exhibits a finer grain structure,since DCT might effectively alleviate the residual stress in FSW 2198 alloy and thus decrease the driving force for grain coarsening in subsequent aging ***,DCT generates dislocation multiplication,which provides more preferential nucleation sites for T1 （Al2CuLi） phase during subsequent aging treatment,resulting in high-density fine T1 phases and thin precipitate-free zone within DAT *** reasonable microstructure leads to DAT alloy possessing better strength-ductility combination compared to AT alloy.

关键词： Al–Li alloy Deep cryogenic treatment Friction stir welding Tensile properties