Synthesis of novel high-entropy diborides with high-efficiency electromagnetic wave absorption and excellent thermal stability  

作　　者：Chencheng Liu Qingyun Chen Peng Sun Xingye Wang Shuyi Zeng Qijie Chen Tong Zhu Yi Zhu Wenlong Zhang Hui Song Yuezhong Wang Kazuhito Nishimura Huasong Liu Nan Jiang 

机构地区：[1]College of Physics and Electronic Information Engineering,Guilin University of Technology,Guilin 541004,China [2]State Key Laboratory of Advanced Marine Materials,Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China [3]Tianjin Key Laboratory of Optical Thin Films,Tianjin Jinhang Technical Physics Institute,Tianjin 300308,China

出　　处：《Journal of Advanced Ceramics》2025年第2期185-197,共13页先进陶瓷(英文)

基　　金：supported by the National Key R&D Program of China(No.2024YFB3816600);the Guangxi Natural Science Foundation(No.2022GXNSFAA035527);the Natural Science Foundation of Tianjin(Nos.23JCZDJC00150 and 22JCZDJC00080);the Science and Technology Major Project of Ningbo(No.2021Z123);the Yongjiang Talent Introduction Programme(No.2021A-108-G);the Youth Fund of the Chinese Academy of Sciences(No.JCPYJJ-22030);Guilin University of Technology Research Startup Fund(No.RD2100000621).

摘　　要：Ceramic materials have obvious advantages in thermal stability,but impedance mismatch limits their ability to attenuate electromagnetic(EM)waves.Herein,a novel series of high-entropy(V_(0.2)Nb_(0.2)Zr_(0.2)Ta_(0.2)X_(0.2))B_(2)(X=Mo,Ti,and Hf)ceramics were successfully synthesized via ultrafast high-temperature sintering(UHS)apparatus based on joule heating.The results indicated that the effect of high-entropy component on the magnetic loss of the system was relatively small,but the effect on the dielectric loss was larger.Among them,the(V_(0.2)Nb_(0.2)Zr_(0.2)Ta_(0.2)Ti_(0.2))B_(2)(HEB-Ti)sample demonstrated superior absorbing properties due to relatively moderate dielectric loss and optimal EM impedance matching.Moreover,because of its relatively moderate attenuation constant,it could achieve the maximum penetration of the EM wave and the minimum reflection after absorbing wave.As a result,the minimum reflection loss(RL_(min))was as low as−40.7 dB,and the effective absorption band covered the entire low-frequency range from 2 to 8 GHz.Its excellent absorption performance was mainly due to the synergistic effect of various dielectric attenuation mechanisms,including defect polarization,dipole polarization,and conduction loss.Furthermore,thermogravimetric(TG)analysis showed that the sample exhibited excellent thermal stability and could withstand temperatures up to 550℃in air and 1000℃in an argon gas environment.The relevant work could provide meaningful references for the design of new high-performance ceramic wave-absorbing materials.

关 键 词：high-entropy diborides(HEBs) ultrafast high-temperature sintering(UHS) electromagnetic(EM)wave absorption impedance matching 

分 类 号：TQ174.75[化学工程—陶瓷工业]