Enabling highly efficient and broadband electromagnetic wave absorption by tuning impedance match in high-entropy transition metal diborides (HETMB_(2))  

作　　者：Weiming ZHANG Fu-Zhi DAI Huimin XIANG Biao ZHAO Xiaohui WANG Na NI Rajamallu KARRE Shijiang WU Yanchun ZHOU 

机构地区：[1]Science and Technology on Advanced Functional Composite Laboratory,Aerospace Research Institute of Materials&Processing Technology,Beijing 100076,China [2]Henan Key Laboratory of Aeronautical Materials and Application Technology,School of Material Science and Engineering,Zhengzhou University of Aeronautics,Zhengzhou 450046,China [3]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [4]Key Lab of Education Ministry for Power Machinery and Engineering,School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [5]Zibo Firststar New Material Incorporated Co.,Ltd.,Zibo 255000,China

出　　处：《Journal of Advanced Ceramics》2021年第6期1299-1316,共18页先进陶瓷（英文）

基　　金：supports from the National Natural Science Foundation of China(Grant Nos.51972089,51672064,and U1435206).

摘　　要：The advance in communication technology has triggered worldwide concern on electromagnetic wave pollution.To cope with this challenge,exploring high-performance electromagnetic(EM)wave absorbing materials with dielectric and magnetic losses coupling is urgently required.Of the EM wave absorbers,transition metal diborides(TMB2)possess excellent dielectric loss capability.However,akin to other single dielectric materials,poor impedance match leads to inferior performance.High-entropy engineering is expected to be effective in tailoring the balance between dielectric and magnetic losses through compositional design.Herein,three HE TMB2 powders with nominal equimolar TM including HE TMB2-I(TM=Zr,Hf,Nb,Ta),HE TMB2-2(TM=Ti,Zr,Hf,Nb,Ta),and HE TMB2-3(TM=Cr,Zr,Hf,Nb,Ta)have been designed and prepared by one-step boro/carbothermal reduction.As a result of synergistic effects of strong attenuation capability and impedance match,HE TMB2-1 shows much improved performance with the optimal minimum reflection loss(RL_(min))of-59.6 dB(8.48 GHz,2.68 mm)and effective absorption bandwidth(EAB)of 7.6 GHz(2.3 mm).Most impressively,incorporating Cr in HE TMB2-3 greatly improves the impedance match over 1-18 GHz,thus achieving the RLmin of-56.2 dB(8.48 GHz,2.63 mm)and the EAB of 11.0 GHz(2.2 mm),which is superior to most other EM wave absorbing materials.This work reveals that constructing high-entropy compounds,especially by incorporating magnetic elements,is effectual in tailoring the impedance match for highly conductive compounds,i.e.,tuning electrical conductivity and boosting magnetic loss to realize highly efficient and broadband EM wave absorption with dielectric and magnetic coupling in single-phase materials.

关 键 词：transition metal diboride(TMB2) high-entropy(HE)ceramics electronic structure microwave absorption dielectric and magnetic losses coupling 

分 类 号：TB34[一般工业技术—材料科学与工程]