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Journal of Materials Science & Technology 2023年第1期132卷 90-99页

作者： Wanjia Li Wangchang Li Yao Ying Jing Yu Jingwu Zheng Liang Qiao Juan Li shenglei che College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014China Research Center of Magnetic and Electronic Materials Zhejiang University of TechnologyHangzhou 310014China

The nano-iron nitride soft magnetic material has excellent magnetic properties and is expected to be a brilliant electromagnetic wave ***,how to fully exploit its wave-absorbing potential re-mains a thought-provoking ***,we have synthesized Fe/Fe_(4)N@SiO_(2)nanomagnetic core-shell materials with different Fe/Fe_(4)N ratios by performing nitridation reactions at different ***,the flower-like core-shell Fe/Fe_(4)N@SiO_(2)structure was obtained by the etching ***,with the synergy of the excellent magnetic and dielectric losses,an outstanding absorption performance could be achieved with a minimum refection loss(RL min)of−71.31 dB at the matching thickness of 1.4 mm,and the widest effective absorption bandwidth(EAB max)of 6.1 GHz less than−10 dB was realized at 1.16 ***,this material also shows a preeminent advance in corrosion resistance to adapt to harsh ***,this iron nitride flower-like core-shell structure exhibits great potential in microwave absorption in harsh conditions.

关键词： Fe/Fe_(4)N@SiO_(2) Flower-like core-shell structure Multifunctions Ultrathin microwave absorber

Interface engineering constructs oxide composite bulkγ'-Fe_(4 )N magnetic alloys with high resistivity:Superior magnetization and manufacturability

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Journal of Materials Science & Technology 2024年第8期175卷 212-222页

Soft magnetic material with high saturation magnetization(Ms)and high resistance(ρ)is vital to improve the power density and conversion efficient of modern electrical magnetic ***,increasing Ms is always at the expense of high resistivity,such as soft magnetic alloys substitute for the *** this work,the superior comprehensive electromagnetic properties,namely the close association of high saturation magnetization and high resistivity,are combined in a new way in a newly Fe-N based magnetic materials.A high resistance oxide interface engineering was constructed between the conducting ferromagnetic phases in the process of spark plasma sintering(SPS)to achieve superior electromagnetic *** ZnO compositeγ’-Fe_(4) N bulk has a maximum resistivity of 220μΩ cm and a Ms of up to 156.02 emu/g,while the TiO_(2)compositeγ’-Fe_(4) N bulk has a maximum resistivity of 379μcm and a Ms of 149.7 emu/*** research findings offer valuable insights for the advancement of the next generation of soft magnetic materials,which hold significant potential for use in high-frequency,high-efficiency,and energy-saving power equipment applications.

关键词： Compositeγ’-Fe_(4)N bulk Nitriding mechanism SPS Saturation magnetization Resistivity

Enhancement mechanism of maximum energy product in hot-deformed Nd-Fe-B magnets by addition of ferromagnetic substances

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Journal of Rare Earths 2023年第12期41卷 1984-1989,I0006页

作者： Lian Wu Xianshuang Xia Wenzong Yin Xu Tang Jinyun Ju Yeyuan Du Renjie chen Zhiyi Xu shenglei che Aru Yan College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou310034China Research Center of Magnetic and Electronic Materials Zhejiang University of TechnologyHangzhou310034China CISRI&NIMTE Joint Innovation Center for Rare Earth Permanent Magnets Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of Sciences Beijing100049China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China Institute of Physics Chinese Academy of SciencesBeijing100190China

It has been proved that the maximum magnetic energy product(BH)maxof hot-deformed Nd-Fe-B magnets can be effectively improved by adding substances with either high melting point or high saturation *** this work,we selected a ferromagnetic nano Fe_(55)Ni_(28)Co_(17) alloy powders with both high melting point and high saturation magnetization as the dopant to improve the(BH)*** the addition of 1 wt% FeNiCo,the remanence increases by over 5%(from 1.36 to 1.44 T),resulting in a significant enhancement of(BH)maxfrom 355 to 396 kJ/m^(3)(from 44.6 to 49.7 MGOe).Microstructure observations reveal that the texture of grain alignment is improved,the concentrations of ferro magnetic elements(Fe,Ni,and Co) in the main phase and intergranular phase are increased so that the magnetization behavior of hot-deformed magnet changes(more easily shows reversible magnetization behaviors),which are the reasons why the high maximum energy product of hot-deformed magnet,is obtained.

关键词： Nd-Fe-B Ferromagnetic substance FeNiCo alloys Magnetic properties Rareearths

Enhanced maximum energy product of(SmY)FeN caused by abundant yttrium doping

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Journal of Rare Earths 2020年第10期38卷 1060-1068,I0002页

作者： Jianwei Xu jingwu Zheng Haibo chen Liang Qiao Yao Ying Wei Cai Wangchang Li Jjing Yu Min Lin shenglei che Research Center of Magnetic and Electronic Materials College of Materials Science and Engineering.Zhejiang University of TechnologyHangzhou 310014China Hangzhou Haisheng Technology Co. LtdHangzhou 310019China Key Laboratory of Magmetic Materials and Devices.Ningbo Institute of Material Technologv&Engineering.Chinese Academy of Science Ningbo 315201China

Replacement of samarium(Sm) with abundant yttrium(Y) can help solve the potential shortage of Sm in the preparation of promising Sm2 Fe17 Nx *** this article,phase composition,microstructure and magnetic properties of(Sm1-yYy)2 Fe17Nx(y=0,0.2,0.4,0.6,0.8,1.0) were *** energy product(BH)max is improved when less than 40 at% Y is doped in(Sm1-yYy)2 Fe17Nx *** particular,when 20 at% Y replaces Sm,(BH)max of(Sm1-yYy)2 Fe17Nx powder increases by 15.1% from 131.7 to151.6 kJ/*** effect of annealing temperature on the structural properties of high Y doping(Sm0.6Y0.4)2 Fe17 and the magnetic properties of the corresponding nitrides were subsequently *** the RE2 Fe17 phase grain combination process,the interlaced structure of the rhombohedral Th2 Zn17-type structural phase and the hexagonal Th2 Ni17-type structural phase is *** to shortrange exchange coupling,the nitride with the highest content of two interlaced RE2 Fe17 phases has the highest magnetic properties:Br=1.23 T,HcJ=443.9 kA/m and(BH)max=197.6 kJ/m3.

关键词： Sm2Fe17Nx Y substitution Maximum energy product Annealing temperature Coexisting RE2Fe17 phases Rare earths

Corrosion mechanism of H_2O on Sm_2Fe_(17) and nitrogenation process of corroded Sm_2Fe_(17)

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Journal of Rare Earths 2019年第6期37卷 638-644页

作者： Jianwei Xu Jingwu Zheng Haibo chen Liang Qiao Yao Ying Wei Cai Wangchang Li Jing Yu Min Lin shenglei che Research Center of Magnetic and Electronic Materials College of Materials Science and EngineeringZhejiang University of Technology Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Material Technology & EngineeringChinese Academy of Sciences

Sm_2 Fe_(17) prepared by reduction-diffusion method needs to be washed with water to remove calcium oxide. Electrochemical corrosion occurs when Sm_2 Fe_(17) powder is in contact with liquid water. Corrosion mechanism of H_2 O on Sm_2 Fe_(17) powder and nitrogenation process of corroded Sm_2 Fe_(17) were studied by analyzing the structure and morphology. It is indicated that the metallic hydroxide forms and deposits on the Sm_2 Fe_(17) powder surfaces during water corrosion. At the same time, oxygen and hydrogen enter the unit cell of Sm2 Fe_(17), causing a slight increase in Curie temperature. In the subsequent nitriding process,the hydroxide is dehydrated and hydrogen is desorbed. The resulting oxide reacts with Sm_2 Fe_(17)N_x to form a-Fe and Sm_2 O_3. Thermodynamic calculations using the HSC chemistry 6.0 software indicate that the reaction can occur spontaneously. The effect of water corrosion on the magnetic properties of the nitride can be eliminated by hydrogen reduction prior to nitriding.

关键词： Sm2Fe17 Nitrogenation Reduction-diffusion method Water corrosion α-Fe formation Rare earths

面向5G应用第3代半导体功率器件的高频低功耗MnZn铁氧体研究进展

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硅酸盐学报 2023年第4期51卷 949-956页

作者：李兆程应耀车声雷浙江工业大学材料科学与工程学院磁电功能材料研究所杭州310014

随着5G通信技术的发展和第3代宽禁带半导体广泛的商用,功率电子器件朝着高频化、小型化和高能效化的方向加速发展.MnZn铁氧体作为功率电子器件的核心材料,成为学术界和产业界在高频软磁材料方面研究的焦点.本综述主要介绍近年来MnZn铁... 详细信息

随着5G通信技术的发展和第3代宽禁带半导体广泛的商用,功率电子器件朝着高频化、小型化和高能效化的方向加速发展.MnZn铁氧体作为功率电子器件的核心材料,成为学术界和产业界在高频软磁材料方面研究的焦点.本综述主要介绍近年来MnZn铁氧体在高频化方向上最新的研究进展,包括通过主成分设计、添加剂调控和低温烧结工艺等手段,实现高频、宽温和低损耗等特性,以及高频下MnZn铁氧体损耗的应力敏感性.随着高频损耗发生机制研究的深入,今后5到10年内将会开发出更多的在0.5 MHz以上的高频和更高的磁通密度下表现出更低损耗的MnZn铁氧体新材料,并迅速应用于通信电源等领域.

关键词：软磁铁氧体 MnZn铁氧体高频功率损耗

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Tuning crystal structure and magnetic property of dispersible FePt intermetallic nanoparticles

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Science China Materials 2018年第7期61卷 961-968页

作者： Jing Yu Weiliang Gao Fei Liu Yanmin Ju Fan Zhao Ziyu Yang Xin Chu shenglei che Yanglong Hou College of Materials Science and Engineering Zhejiang University of Technology Hangzhou 310014 China Department of Materials Science and Engineering College of Engineering Peking University Beijing 100871 China Department of Materials Science and Engineering Iowa State University of Science and Engineering Ames 50011 USA

Dispersible FePt intermetallic nanopartides （NPs） with tunable composition were synthesized by thermal annealing of MgO coated A1-FePt （or A1-FePt-Fe304） NPs followed by an acid treatment to remove MgO. High-tem- perature annealing facilitates the conversion of FePt from disordered alloy to ordered intermetaUics. Under the protec- tion of MgO, the diffusion of Fe and Pt atoms was limited, making it possible for the atom reconstruction in the lattice to give discrete FePt intermetaUic NPs after a facile acid etching process. FePt intermetallic NPs formed face-centered cubic and face-centered tetragonal structures with their magnetic properties tuned by composition. The saturation magnetiza- tion was adjusted from 8 to 52 emu g^-1 by increasing the Fe concentration, while the coercivity reached a max/mum of 33 kOe when Fe concentration was 44%. After surface mod- ifications by hydrophilic or hydrophobic molecules containing thiol groups, FePt intermetallic NPs could be dissolved into water or hydrocarbon solvents. The hydrophilic L10-FePt in- termetallic NPs were applied as contrast agents for magnetic resonance imaging, showing a high transverse relaxivity of 328.6 mmo1^-1 L s^-l, which indicated the great potential of FePt intermetallic NPs as molecular probes for cancer diagnosis.

关键词： FePt intermetallic nanoparticles chemical ordering magnetic materials contrast agent

煅烧碳酸盐沉淀前驱物制备YBa_2Cu_3O_(7—δ)超导体的研究

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西安交通大学学报 1989年第5期23卷 47-52页

作者：车声雷蔡灿珍西安交通大学化学与化学工程系

本文研究钇钡铜碳酸盐共沉淀前驱物的物相组成及其煅烧过程。该前驱物是由钇钡碳酸盐和碱式碳酸铜、碱式硝酸铜等组成的混合物。在温度达到700℃之前,铜和钇的化合物先后分解为氧化物,900℃之后开始生成YBa_2Cu_3O_(7-δ),BaCO_3的分解... 详细信息

本文研究钇钡铜碳酸盐共沉淀前驱物的物相组成及其煅烧过程。该前驱物是由钇钡碳酸盐和碱式碳酸铜、碱式硝酸铜等组成的混合物。在温度达到700℃之前,铜和钇的化合物先后分解为氧化物,900℃之后开始生成YBa_2Cu_3O_(7-δ),BaCO_3的分解是该反应的限速步骤。为了制备单相的YBa_2Cu_3O_(7-δ)粉体,应降低原料中BaCO_3的粒度,并在流动氧气或流动空气中进行煅烧。

关键词：超导体碳酸盐共沉淀煅烧

用于高频电机磁芯的金属软磁复合材料研究进展

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材料导报 2018年第7期32卷 1139-1144页

作者：李旺昌王兆佳李晶鑫车声雷浙江工业大学材料科学与工程学院磁电功能材料研究所杭州310000

金属软磁复合材料(Soft magnetic composite,SMC)具有较高的电阻率和饱和磁感应强度,在高速电机、开关电源和电力工业等方面有广泛的应用,尤其是作为高速电机磁芯材料潜力巨大。研制能效更高、体积更小、应用范围更广的新型软磁复合材... 详细信息

金属软磁复合材料(Soft magnetic composite,SMC)具有较高的电阻率和饱和磁感应强度,在高速电机、开关电源和电力工业等方面有广泛的应用,尤其是作为高速电机磁芯材料潜力巨大。研制能效更高、体积更小、应用范围更广的新型软磁复合材料成为当前一大热点。本文介绍了软磁复合材料的生产工艺、结构特征以及金属磁性材料和绝缘包覆材料,阐述了各要素对材料性能的影响,概述了软磁复合材料在电机中的应用,并综述了近几年软磁复合材料的发展。

关键词：软磁复合材料(SMC) 有机/无机包覆高速电机磁芯

多孔氧化铝担持NiFe_(2)O_(4)水热解制氢

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浙江工业大学学报 2021年第3期49卷 324-331页

作者：应耀王春阳王能超车声雷浙江工业大学材料科学与工程学院浙江杭州310014

氢能源作为一种清洁、高效的绿色能源在替代传统化石燃料上被寄予厚望。铁氧体等多价氧化物水热解制氢是利用太阳光热绿色制氢的主要途径之一,目前的主要问题是热循环过程中氧化物的烧结引起的比表面积减少导致制氢能力下降,因此循环寿... 详细信息

氢能源作为一种清洁、高效的绿色能源在替代传统化石燃料上被寄予厚望。铁氧体等多价氧化物水热解制氢是利用太阳光热绿色制氢的主要途径之一,目前的主要问题是热循环过程中氧化物的烧结引起的比表面积减少导致制氢能力下降,因此循环寿命不长。为了延长循环寿命,尝试将镍铁氧体担持于多孔氧化铝陶瓷上以抑制其烧结。研究发现:多孔氧化铝陶瓷担持的铁氧体,其烧结现象明显缓解,循环寿命有所提高。通过比较多孔氧化铝担持镍铁氧体与氧化锆掺杂镍铁氧体在不同温度下的制氢能力及循环次数,发现在1250℃时多孔氧化铝陶瓷担持镍铁氧体的循环寿命有明显提高,制氢能力与循环寿命的综合性能最佳。

关键词：两步式热化学循环制氢 NiFe_(2)O_(4) 循环寿命多孔氧化铝