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Achieving ultra-broadband electromagnetic wave absorption in high-entropy transition metal carbides (HE TMCs)

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Journal of Advanced Ceramics 2022年第4期11卷 545-555页

作者： Weiming ZHANG Huimin XIANG Fu-Zhi DAI Biao ZHAO Shijiang WU Yanchun ZHOU Science and technology on Advanced Functional Composite laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China henan key laboratory of aeronautical materials and application technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China Zibo Firststar New material Incorporated Co. Ltd.Zibo 255000China

Electronic devices pervade everyday life,which has triggered severe electromagnetic(EM)wave pollution.To face this challenge,developing EM wave absorbers with ultra-broadband absorption capacity is critically required.Currently,nano-composite construction has been widely utilized to realize impedance match and broadband absorption.However,complex experimental procedures,limited thermal stability,and interior oxidation resistance are still unneglectable issues.Therefore,it is appealing to realize ultra-broadband EM wave absorption in single-phase materials with good stability.Aiming at this target,two high-entropy transition metal carbides(HE TMCs)including(Zr,Hf,Nb,Ta)C(HE TMC-2)and(Cr,Zr,Hf,Nb,Ta)C(HE TMC-3)are designed and synthesized,of which the microwave absorption performance is investigated in comparison with previously reported(Ti,Zr,Hf,Nb,Ta)C(HE TMC-1).Due to the synergistic effects of dielectric and magnetic losses,HE TMC-2 and HE TMC-3 exhibit better impedance match and wider effective absorption bandwidth(EAB).In specific,the exclusion of Ti element in HE TMC-2 endows it optimal minimum reflection loss(RL_(min))and EAB of−41.7 dB(2.11 mm,10.52 GHz)and 3.5 GHz(at 3.0 mm),respectively.Remarkably,the incorporation of Cr element in HE TMC-3 significantly improves the impedance match,thus realizing EAB of 10.5,9.2,and 13.9 GHz at 2,3,and 4 mm,respectively.The significance of this study lays on realizing ultra-broadband capacity in HE TMC-3(Cr,Zr,Hf,Nb,Ta),demonstrating the effectiveness of high-entropy component design in tailoring the impedance match.

关键词： transition metal carbide(TMC) high-entropy ceramics electromagnetic(EM)wave absorption dielectric and magnetic loss coupling ultra-broadband absorption

One-step and Continuous Fabrication of Coaxial Piezoelectric Fiber for Sensing application

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Chinese Journal of Polymer Science 2023年第11期41卷 1778-1785,I0009页

作者： Shuai-Shuai Gui Bing-Xu Da Fei Peng Guo-Qiang Zheng Kun Dai Chun-Tai Liu Chang-Yu Shen College of materials Science and Engineering Key Laboratory of Material Processing and Mold(Ministry of Education)Henan Key Laboratory of Advanced Nylon Materials and ApplicationZhengzhou UniversityZhengzhou 450001China

Although there has been rapid advancement in piezoelectric sensors,challenges still remain in developing wearable piezoelectric sensors by a one-step,continuous and environmentally friendly method.In this work,a 1D flexible coaxial piezoelectric fiber was directly fabricated by melt extrusion molding,whose core and sheath layer are respectively slender steel wire(i.e.,electrode)and PVDF(i.e.,piezoelectric layer).Moreover,such 1D flexible coaxial piezoelectric fiber possesses short response time and high sensitivity,which can be used as a selfpowered sensor for bending and vibration sensing.More interestingly,such 1D flexible coaxial piezoelectric fiber(1D-PFs)can be further endowed with 3D helical structure.Moreover,a wearable and washable motion monitoring system can be constructed via braiding such 3D helical piezoelectric fiber(3D-PF)into commercial textiles.This work paves a new way for developing 1D and 3D piezoelectric fibers through a one-step,continuous and environmentally friendly method,showing potential applications in the field of sensing and wearable electronics.

关键词： Coaxial piezoelectric fiber Melt extrusion molding Bending and vibration sensing Motion monitoring system

In-situ grown Ni Co bimetal anchored on porous straw-derived biochar composites with boosted microwave absorption properties

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International Journal of Minerals,Metallurgy and materials 2023年第3期30卷 515-524页

作者： Yuanyuan Zhou Zhongyi Bai Xiangyang Yang Wei Liu Bingbing Fan Zhikai Yan Xiaoqin Guo henan key laboratory of aeronautical materials and application technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China School of Chemical&Environmental Engineering China University of Mining&Technology(Beijing)Beijing 100083China School of material Science and Engineering Zhengzhou UniversityZhengzhou 450001China

With the gradually increasing protection awareness about electromagnetic pollution,the demand for absorbing materials with renewability and environmental friendliness has attracted widespread attention.In this work,composites consisting of straw-derived biochar combined with NiCo alloy were successfully fabricated through high-temperature carbonization and subsequent hydrothermal reaction.The electromagnetic parameters of the porous biocarbon/NiCo composites can be effectively modified by altering their NiCo content,and their improved absorbing performance can be attributed to the synergy effect of magnetic-dielectric characteristics.An exceptional reflection loss of-27.0 dB at 2.2 mm thickness and an effective absorption bandwidth of 4.4 GHz(11.7-16.1 GHz)were achieved.These results revealed that the porous biocarbon/NiCo composites could be used as a new generation absorbing material because of their low density,light weight,excellent conductivity,and strong absorption.

关键词： straw-derived biochar microwave absorption interfacial polarization magnetic loss bimetallic NiCo impedance matching

Growth of magnetic metals on carbon microspheres with synergetic dissipation abilities to broaden microwave absorption

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Journal of materials Science & technology 2022年第12期107卷 100-110页

作者： Biao Zhao Yang Li Qingwen Zeng Bingbing Fan Lei Wang Rui Zhang Renchao Che laboratory of Advanced materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438China Department of materials Science Fudan UniversityShanghai 200438China henan key laboratory of aeronautical materials and application technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhouHenan 450046China School of material Science and Engineering Zhengzhou UniversityZhengzhouHenan 450001China State key laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Microwave absorption(MA) materials have been captured extensive attentions due to the serious electromagnetic(EM) pollution. Numerous interests focus on the MA performances of core-shell structural composites with magnetic constituents as cores and dielectric constituents as shells, which inevitably suppressed the magnetic coupling causing the decrease of magnetic loss to some extent. Herein, the coreshell structural carbon(C) microsphere/magnetic metal composites were fabricated through the combination of an electrostatic assembly approach and subsequent in-situ reduction reaction. The complex permittivity and permeability of core-shell C@magnetic metal composite system can be effective adjusted by the constituent and microstructure of shells. Thanks to the distinct magnetic coupling from the subtle designed structures and the promotion of the magnetic-dielectric synergy, the C@magnetic metal composite exhibited enhanced MA properties. The optimal reflection loss(RL) of C@Ni composite was-54.1 dB with a thickness of 3.4 mm, meanwhile the effective absorbing band could reach over 5.5 GHz at only a1.8 mm thickness. Broad absorption bandwidth with RL below-10 d B could achieve 6.0 GHz and 6.7 GHz for C@Co and C@Ni Co composites with a thin 2.1 mm thickness, respectively. Our exciting findings might lead a guide on the novel structure design for the functional core-shell structural composites used for microwave absorption.

关键词： Microwave absorption Core-shell structure C@magnetic metal composite Interfacial polarization Magnetic coupling

Microwave synthesis of chain-like zircona nanofibers through carbon-induced self-assembly growth

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Frontiers of materials Science 2017年第4期11卷 353-357页

作者： Wanyu ZHAO Jian LI Bingbing FAN Gang SHAO Hailong WANG Bozhen SONG Shengnan WEI Rui ZHANG School of materials Science and Engineering Zhengzhou University Zhengzhou 450001 China Henan Key Laboratory of Aeronautical Material and Application Technology Zhengzhou University of Aeronautics Zhengzhou 450046 China

Chain-like zircona （ZrO2） nanofibers were prepared by microwave sinter- ing without any surfactants or solid templates. Microwave sintering was conducted in a multimode microwave cavity with TE666 resonant mode at 2.45 GHz. Carbon particles were used to activate unique thermal processes when mixed with ZrO2 precursor. The sintering condition was at 1300℃ for 10 min. Samples were characterized by XRD, SEM, TEM techniques. It was found that both monolithic and tetragonal ZrO2 co-existed in samples prepared from the mixture of ZrO2 precursors and carbon by either microwave or conventional sintering. Only m-ZrO2 exists in samples prepared by ZrO2 precursors without carbon. ZrO2 appeared as chain-like nanofibers, which might be attributed to a so- called carbon-induced self-assembly growth mechanism.

关键词： ZrO2 chain-like nanofibers microwave sintering carbon-induced self-assembly growth

One-step synthesis and electromagnetic absorption properties of high entropy rare earth hexaborides(HE REB6)and high entropy rare earth hexaborides/borates(HE REB6/HE REB03)composite powders

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Journal of Advanced Ceramics 2021年第1期10卷 62-77页

作者： Weiming ZHANG Biao ZHAO Huimin XIANG Fu-Zhi DAI Shijiang WU Yanchun ZHOU Science and technology on Advanced Functional Composite laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China henan key laboratory of aeronautical materials and application technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China Zibo Firststar New material Incorporated Co. Ltd.Zibo 255000China

Considering the emergence of severe electromagnetic interference problems,it is vital to develop electromagnetic(EM)wave absorbing materials with high dielectric,magnetic loss and optimized impedance matching.However,realizing the synergistic dielectric and magnetic losses in a single phase material is still a challenge.Herein,high entropy(HE)rare earth hexaborides(REB6)powders with coupling of dielectric and magnetic losses were designed and successfully synthesized through a facial one-step boron carbide reduction method,and the effects of high entropy borates intermedia phases on the EM wave absorption properties were investigated.Five HE REB6 ceramics including(Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6,(Ce0.2Hu0.2Sm0.2Er0.2Yb0.2)B6,(Ce0.2Y0.2Eu0.2Er0.2Yb0.2)B6,(Ce0.2Ya2Sm0.2Eu0.2Yb0.2)B6,and(Nd0.2Y0.2Sm0.2Eu0.2Yb0.2)B6 possess CsCl-type cubic crystal structure,and their theoretical densities range from 4.84 to 5.25 g/cm^(3).(Ce02Y0.2Sm0.2Er0.2Yb02)B6 powders with the average particle size of 1.86 jim were found to possess the best EM wave absorption properties among these hexaborides.The RLmin value of(Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6 reaches-33.4 dB at 11.5 GHz at thickness of 2 mm;meanwhile,the optimized effective absorption bandwidth(EAB)is 3.9 GHz from 13.6 to 17.5 GHz with a thickness of 1.5 mm.The introduction of HE REB03(RE=Ce,Y,Sm,Eu,Er,Yb)as intermediate phase will give rise to the mismatching impedance,which will further lead to the reduction of reflection loss.Intriguingly,the HEREB6/HEREB03 still possess wide effective absorption bandwidth of 4.1 GHz with the relative low thickness of 1.7 mm.Considering the better stability,low density,and good EM wave absorption properties,HE REB6 ceramics are promising as a new type of EM wave absorbing materials.

关键词： high entropy rare earth hexaborides(HE REB6) one-step synthesis electromagnetic wave absorbing properties synergistic dielectric and magnetic losses wide effective absorption bandwidth

Superconducting and structural properties of the phosphorus-rich Nb_(2)P_(5) superconductor under high pressure

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钨科技(英文) 2023年第3期5卷 364-369页

作者： Lei-Ming Chen Fang-Huang Wei Yan-Hong Chen Hang-Qi Liu Yang Xu Bo-Yu Chen Can-Li Dai Yu-Bo Zhang Zhen-Hai Yu School of materials Science and Engineering Henan Key Laboratory of Aeronautic Materials and Application TechnologyZhengzhou University of AeronauticsZhengzhou 450046China Henan Key Laboratory of Aeronautical Material and Application Technology Zhengzhou University of AeronauticsZhengzhou 450046China Yongcheng City Vocational Education Center Shangqiu 476600China Kaixue Cold Chain Logistics Co. LtdZhengzhou 451450China Minjiang Collaborative Center for Theoretical Physics College of Physics and Electronic Information EngineeringMinjiang UniversityFuzhou 350108China School of Physical Science and technology ShanghaiTech UniversityShanghai 201210China

Nb_(2)P_(5) is a recently discovered Bardeen,Cooper,Schrieffer theory s-wave superconductor hosting nontrivial topological nodal-line structure,which could serve as an excellent platform for studying the interplay between the superconductivity and nontrivial topological states.We report herein the superconducting and structural properties of Nb2P5studied by measuring the electrical resistivity and structure under high pressure up to ~28 GPa and performing first principles calculations.The superconducting transition temperature TCdecreases with applied pressure,and reaches a minimum of 1.9 K at ~20.0 GPa,followed by a continuous enhancement up to 50.0 GPa without saturation.Furthermore,at pressures above ~8.2 GPa,it is likely that a second superconducting transition appears and coexists with the initial one even up to~28 GPa.Theoretical calculations rule out the correlation between the second superconducting-like transition and structure.Moreover,the Nb2P5showed remarkable axial anisotropic compressibility,in which the b-axis is more compressible than the a-and c-axes.The variation of TCis discussed via considering the evolution of density of states around the Fermi level and the phonon spectrum.

关键词： Phosphorus-rich superconductor Superconducting transition temperature High-pressure measurement First principles calculations

Processing and properties of PcBN composites fabricated by HPHT using PSN and Al as sintering additive

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稀有金属：英文版 2020年第5期39卷 570-576页

作者： Ming-Liang Li Li-Xing Liang Hai-Long Wang Peng-Bo Zhao Xiao-Tong Zhao Gang Shao Rui Zhang School of materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Henan Key Laboratory of Aeronautical Material and Application Technology Zhengzhou University of AeronauticsZhengzhou 450052China

Dense polycrystalline cubic boron nitride(PcBN)composites were fabricated by high-pressure and high-temperature(HPHT)sintering using polysilazane(PSN)and Al as sintering additive.After high-energy ball milling,the cBN fine particles were uniformly coated with PSN by ultrasonic treatment.After thermocuring and pyrolysis,the cBN–SiCN particles were mixed with Al The PcBN composites were prepared after sintering a1450°C for 10 min with a pressure of 5 GPa.The refining effect of high-energy ball milling on the c BN particles was studied by scanning electron microscopy(SEM)and laser particle size analyzer.The oxidation of the cBN particles after milling was investigated by nitrogen–oxygen analyzer.The phase composition and microstructure of the sintered PcBN composites were investigated by X-ray diffractometer(XRD)and SEM.The main phases of the sintered PcBN composites are c BN,AlN,SiC and Si3N4The conversion of cBN to hBN was inhibited by the formation of AlN.The mechanical properties of the sintered PcBN composites were improved by the appearance of SiC and Si3N4.The density and mechanical properties of the PcBN composites both increased with the content of the cBN particles increasing.The sintered sample with 60 wt%cBN,30 wt%PSN and 10 wt%Al showed the best results density of 99.7%,Vickers’hardness of(25.2±0.8)GPa and flexural strength of(602±15)MPa.

关键词： Polycrystalline cubic boron nitride Highpressure and high-temperature sintering High-energy ball milling Mechanical properties

High-entropy spinel ferrites MFe_(2)O_(4)(M=Mg,Mn,Fe,Co,Ni,Cu,Zn)with tunable electromagnetic properties and strong microwave absorption

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Journal of Advanced Ceramics 2022年第5期11卷 754-768页

作者： Jiabin MA Biao ZHAO Huimin XIANG Fu-Zhi DAI Yi LIU Rui ZHANG Yanchun ZHOU henan key laboratory of aeronautical materials and application technology School of Materials Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China Science and technology on Advanced Functional Composite laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China School of material Science and Engineering Shaanxi University of Science and TechnologyXi'an 710021China School of materials Science and Engineering Luoyang Institute of Science and TechnologyLuoyang 471023China

Ferrites are the most widely used microwave absorbing materials to deal with the threat of electromagnetic(EM)pollution.However,the lack of sufficient dielectric loss capacity is the main challenge that limits their applications.To cope with this challenge,three high-entropy(HE)spineltype ferrite ceramics including(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4),(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))Fe_(2)O_(4),and(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Zn_(0.2))Fe_(2)O_(4)were designed and successfully prepared through solid state synthesis.The results show that all three HE MFe_(2)O_(4) samples exhibit synergetic dielectric loss and magnetic loss.The good magnetic loss ability is due to the presence of magnetic components;while the enhanced dielectric properties are attributed to nano-domain,hopping mechanism of resonance effect and HE effect.Among three HE spinels,(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4)shows the best EM wave absorption performance,e.g.,its minimum reflection loss(RL_(min))reaches-35.10 dB at 6.78 GHz with a thickness of 3.5 mm,and the optimized effective absorption bandwidth(EAB)is 7.48 GHz from 8.48 to 15.96 GHz at the thickness of 2.4 mm.Due to the easy preparation and strong EM dissipation ability,HE MFe_(2)O_(4) are promising as a new type of EM absorption materials.

关键词： high-entropy ceramics(HECs) spinel-type ferrite electromagnetic(EM)wave absorption dielectric loss magnetic loss