High-entropy carbides are increasingly favored as electromagnetic wave-absorbing materials because of their customizable structures and distinctive high-entropy effects.Nonetheless,the influence of entropy changes on ...High-entropy carbides are increasingly favored as electromagnetic wave-absorbing materials because of their customizable structures and distinctive high-entropy effects.Nonetheless,the influence of entropy changes on the absorptive characteristics of high-entropy carbide ceramics remains underexplored.In this work,the impact of increased entropy on the absorption characteristics of stable high-entropy transition metal carbides has been systematically studied.This work prepared three carbides ceramics with different entropy values:(Mo_(1/3)Nb_(1/3)Ta_(1/3))C,(Ti_(1/4)Mo_(1/4)Nb_(1/4)Ta_(1/4))C,and(Zr_(1/5)Ti_(1/5)Mo_(1/5)Nb_(1/5)Ta_(1/5))C.The impact of entropy variation in high-entropy carbide nanowires on their wave-absorbing properties was studied.The results showed excellent electromagnetic wave absorption,achieving a minimum reflection loss of−50.08 dB at 1.8 mm,and demonstrating an effective absorption bandwidth of 4.675 GHz at 1.7 mm.In addition,through detailed structure,morphology,and chemical state characterization,as well as wave absorption capability testing,research indicates that high-entropy carbides can effectively regulate defects by adjusting the size of entropy,leading to lattice distortion,discontinuous lattice fringes,and vacancies.The presence of these defects enhances the polarization loss and balances the excessively high dielectric constant of high-entropy carbide ceramics.Additionally,the design of one-dimensional structures facilitates carrier migration,thereby increasing conductive loss.Collectively,these factors enhance the ability of the samples to attenuate electromagnetic waves.This study lays a theoretical foundation and provides experimental guidance for developing new high-performance materials for electromagnetic wave absorption.展开更多
基金sponsored by the National Natural Science Foundation of China(NSFC)(U21A2064,52202064)the Scientific Research Team Plan of Zhengzhou University of Aeronautics(23ZHTD01002)+2 种基金the International Science and Technology Cooperation Project of Henan Province(241111520800)the Science Foundation for The Excellent Youth Scholars of Henan Province(212300410089),the Henan Key Laboratory of Aeronautical Material and Technology Open Foundation(ZHKF-230101)the ZUA Innovation Fund for Graduate Education(2024CX106,2024CX124).
文摘High-entropy carbides are increasingly favored as electromagnetic wave-absorbing materials because of their customizable structures and distinctive high-entropy effects.Nonetheless,the influence of entropy changes on the absorptive characteristics of high-entropy carbide ceramics remains underexplored.In this work,the impact of increased entropy on the absorption characteristics of stable high-entropy transition metal carbides has been systematically studied.This work prepared three carbides ceramics with different entropy values:(Mo_(1/3)Nb_(1/3)Ta_(1/3))C,(Ti_(1/4)Mo_(1/4)Nb_(1/4)Ta_(1/4))C,and(Zr_(1/5)Ti_(1/5)Mo_(1/5)Nb_(1/5)Ta_(1/5))C.The impact of entropy variation in high-entropy carbide nanowires on their wave-absorbing properties was studied.The results showed excellent electromagnetic wave absorption,achieving a minimum reflection loss of−50.08 dB at 1.8 mm,and demonstrating an effective absorption bandwidth of 4.675 GHz at 1.7 mm.In addition,through detailed structure,morphology,and chemical state characterization,as well as wave absorption capability testing,research indicates that high-entropy carbides can effectively regulate defects by adjusting the size of entropy,leading to lattice distortion,discontinuous lattice fringes,and vacancies.The presence of these defects enhances the polarization loss and balances the excessively high dielectric constant of high-entropy carbide ceramics.Additionally,the design of one-dimensional structures facilitates carrier migration,thereby increasing conductive loss.Collectively,these factors enhance the ability of the samples to attenuate electromagnetic waves.This study lays a theoretical foundation and provides experimental guidance for developing new high-performance materials for electromagnetic wave absorption.
