Interface Strategy To Achieve Tunable High Frequency Attenuation

Abstract

Among all polarizations, the interface polarization effect is the most effective, especially at high frequency. The design of various ferrite/iron interfaces can significantly enhance the materials' dielectric loss ability at high frequency. This paper presents a simple method to generate ferrite/iron interfaces to enhance the microwave attenuation at high frequency. The ferrites were coated onto carbonyl iron and could be varied to ZnFe2O4, CoFe2O4, Fe3O4, and NiFe2O4. Due to the ferrite/iron interface inducing a stronger dielectric loss effect, all of these materials achieved broad effective frequency width at a coating layer as thin as 1.5 mm. In particular, an effective frequency width of 6.2 GHz could be gained from the Fe@NiFe2O4 composite.

Transform between the permeability and permittivity in Ni@C C NbC nanocomposites with enhanced microwave absorption properties

“…Generally, dielectric loss mainly comes from the electron polarization, the ion polarization and the electric dipolar polarization, etc [2,29]. When frequency is in gigahertz range, the electron and the ion polarization are negligible, and the electric dipolar polarization might be a main contributor, which can be expressed by the Debye dipolar polarization [2,29].…”

“…When frequency is in gigahertz range, the electron and the ion polarization are negligible, and the electric dipolar polarization might be a main contributor, which can be expressed by the Debye dipolar polarization [2,29].…”

Emerging in‐plane anisotropic two‐dimensional materials

“…Such fundamental anisotropy between in‐plane and out‐of‐plane can be utilized to exfoliate and study layered materials into 2D limit. The first cleaved 2D material, graphene, has excellent electronic, mechanical, optical, and thermal properties, which has been considered to have promising applications in the fields of flexible electronics, electromagnetic absorption, energy generation and storage . However, the lack of a band gap blocks its applications in digital devices and photodetectors with high performance .…”

Biomass-Derived Porous Carbon-Based Nanostructures for Microwave Absorption

“…boosts the electronic conductivity of biomass-derived PC. According to free electron theory: ε″ = 1/2πρfε 0 , where ρ is the resistivity and ε 0 is the permittivity of vacuum [59][60][61], it can be deduced that the increase in conductivity would enhance the dielectric loss and microwave loss capacity of material. Besides, small amounts of heteroatoms (N, O, P, etc.)…”