Investigation of the Microwave Absorption Properties of Fe Based Nanocomposites

Abstract

The objective of this work was to provide information about the behaviour of Fe-based nanocomposites when exposed to microwaves. It is about rectangular bulk samples of epoxy resin reinforced by nanocrystalline Fe powders and shaped in accordance to the internal section of the R100 metallic waveguide (8.2 to 12.4 GHz) at a fixed thickness of 7 mm. The nanocrystalline Fe powders were obtained by high-energy mechanical milling process using a planetary Retsch PM 400-ball mill. The milling speed was fixed at 200 rpm for three durations and the milling process were performed under Argon atmosphere. The bulk nanocomposites were obtained by dispersion of 30% vol. of the nanocrystalline Fe powders in the resin matrix. Electromagnetic parameters as complex relative dielectric permittivity and magnetic permeability, electric and magnetic loss tangent and reflection loss were calculated using reordered S parameters. The scattering parameters were characterized using a measure cell made off two metallic R100 wave-guides associated to an Agilent 8719 network analyser according to the reflection-transmission technique. The obtained spectra inform on the new electromagnetic properties as well as the absorption characteristic acquired by the bulk nanocomposites due to the presence of the nanocrystalline Fe powders.

Microwave Absorption Properties of Fe₄₀Co₆₀ Based Nanocomposites

“…Corresponding spectra in Fig. 6.a show moderate values with increasing tendency according to frequency for all the samples over the microwaves band [8][9][10][11][12][13][14][15]. The low values are observed for 60h MA duration.…”

“…In summary, in this study, the complex relative dielectric permittivity 𝜀 𝑟 and magnetic permeability 𝜇 𝑟 spectra were investigated in 𝐹𝑒 40 𝐶𝑜 60 based nanocomposites obtained by solution dispersion of nanocrystalline 𝐹𝑒 40 𝐶𝑜 60 in commercial epoxy resin and shaped as thin slabs. The experimental results indicate that the prepared materials show good microwave absorption characteristic over the [8][9][10][11][12][13][14][15] GHz frequency range. The maximum reflection loss is -24 dB observed at 13.75 GHz and reached after 12h of milling.…”

“…The fundamental concept of the reflection/ transmission technique is to sandwich the sample test between two waveguide sections and to carry out a two port scattering measures via the VNA (Keysight Technologies N5222A). The measured Sij scattering were converted in terms of relative dielectric permittivity and magnetic permeability via the Nicholson-Ross-Weir equations expressed in a waveguide structure as follow [12,13]:…”

“…The microwave experiments involved a Network Analyzer (VNA). Obtained results in terms of reflection losses show a good absorbing characteristic over the [8][9][10][11][12][13][14][15] GHz microwaves band.…”

Advanced CuS/g-C3N4/Fe3O4 Nanostructures for Broadband Microwave Absorption

“…Currently, the primary method for countering electromagnetic threats is to employ electromagnetic shielding materials . With this in mind, researchers are actively pursuing the development of innovative absorbing materials that exhibit higher absorption rates, lower densities, and superior chemical stabilities. − The forefront of scientific research currently resides in the exploration of nanoabsorbent materials, composite absorption materials, and intelligent absorbing materials. − …”