The control of undesired electromagnetic radiation in S-and C-band spectra requires novel microwave absorbing materials(MAMs)having high microwave attenuation capability together with optimal impedance matching.CNTs a...The control of undesired electromagnetic radiation in S-and C-band spectra requires novel microwave absorbing materials(MAMs)having high microwave attenuation capability together with optimal impedance matching.CNTs are conformally coated onto the surface of one-dimensional FeCo-based magnetic microchains via electrostatic self-assembly,and then the magnetic inclusions are collectively oriented in matrices by applying an external magnetic field.The proper incorporation of CNTs with magnetic microchains demonstrates a feasible pathway for effectively absorbing microwaves in the S and C band.MAMs consisting of oriented microchains have anisotropic complex permittivity,of which the real part ranges from 6.1 to 30.4 at 2 GHz.When the electric field is parallel to microchains,the 5-mm-thick MAM has an effective absorbing bandwidth(EAB)in the range of 2.3 to 2.9 GHz,and reduces the radar cross section to be lower than-15.9 dB m^(2) from the vertical to the glancing incidence.When the magnetic field is parallel to microchains,the MAM adsorbs C-band microwaves with an EAB of 1.5 GHz,and achieves maximal reflection loss of-46.4 dB.The collective orientation of shape-anisotropic magnetic materials,in addition to the composition and microstructure,is a new variable for the design of effective MAMs.展开更多
基金financial support from the National Natural Science Foundation of China(Nos.U21A2093,and 12104164)partially financed by the Polymer Electro-magnetic Functional Materials Innovation Team of Shaanxi Sanqin Scholars.
文摘The control of undesired electromagnetic radiation in S-and C-band spectra requires novel microwave absorbing materials(MAMs)having high microwave attenuation capability together with optimal impedance matching.CNTs are conformally coated onto the surface of one-dimensional FeCo-based magnetic microchains via electrostatic self-assembly,and then the magnetic inclusions are collectively oriented in matrices by applying an external magnetic field.The proper incorporation of CNTs with magnetic microchains demonstrates a feasible pathway for effectively absorbing microwaves in the S and C band.MAMs consisting of oriented microchains have anisotropic complex permittivity,of which the real part ranges from 6.1 to 30.4 at 2 GHz.When the electric field is parallel to microchains,the 5-mm-thick MAM has an effective absorbing bandwidth(EAB)in the range of 2.3 to 2.9 GHz,and reduces the radar cross section to be lower than-15.9 dB m^(2) from the vertical to the glancing incidence.When the magnetic field is parallel to microchains,the MAM adsorbs C-band microwaves with an EAB of 1.5 GHz,and achieves maximal reflection loss of-46.4 dB.The collective orientation of shape-anisotropic magnetic materials,in addition to the composition and microstructure,is a new variable for the design of effective MAMs.
