Grain Size Influence on Microwave Absorption Properties in Nanocrystalline Fe&lt;sub&gt;40&lt;/sub&gt;Co&lt;sub&gt;60&lt;/sub&gt;

Otmane, Fadhéla; Triaa, Salim; Bergheul, S.; Azzaz, M.

doi:10.4028/www.scientific.net/jnanor.29.49

Cited by 5 publications

(7 citation statements)

References 14 publications

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“…When at 120 °C, the reflection loss (RL) value was −33.34 dB at 8.2 GHz and effective bandwidth (RL< −10 dB) was 2.5 GHz with a matching thickness of 2.0 mm. The absorption property was enhanced to the best at 180 °C, which is obviously higher than other reported results [17,21,22,23], as shown in Table 2. However, the reflection loss (RL) value began to decrease to −39.56 dB at 9.2 GHz at 200 °C.…”

Section: Resultscontrasting

confidence: 66%

The Preparation of FeCo/ZnO Composites and Enhancement of Microwave Absorbing Property by Two-Step Method

et al. 2019

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In this paper, the flower-like FeCo/ZnO composites were successfully firstly prepared by a two-step method, and their microstructures and microwave absorbing properties were characterized. The results show that with an increase of temperature, the content of ZnO loaded on a FeCo/ZnO composite surface was increased. The optimal reflection loss (RL) value can be reached around −53.81 dB at 9.8 GHz, which is obviously superior to results of previous studies and reports, and its effective bandwidth (RL < −10 dB) is 3.8 GHz in the frequency range of 8.7–11.8 GHz with a matching thickness of 1.9 mm. We considered that a large number of lamellar and rod-like ZnO loaded on nano-FeCo single-phase solid solution by two-step method can significantly improve the electromagnetic wave absorption properties.

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Section: Resultscontrasting

confidence: 66%

The Preparation of FeCo/ZnO Composites and Enhancement of Microwave Absorbing Property by Two-Step Method

et al. 2019

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“…These changes express the response of the material's sample to the interaction with the microwave field in the cavity. The resolution of the Maxwell equations for a little modification of the electric field in the cavity leads to the following relations between the material's dielectric properties (𝜀 𝑟 = 𝜀 𝑟 ′ − 𝑗𝜀 𝑟 ′′ ) and the induced changes [9,10]:…”

Section: Resultsmentioning

confidence: 99%

“…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.…”

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confidence: 83%

Microwave Absorption Properties of Fe<sub>40</sub>Co<sub>60</sub> Based Nanocomposites

Boumagouda

Otmane

Hamlati

et al. 2021

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Microwave absorbing materials are applied in stealth, communications and information processing technologies. This kind of material dissipates an electromagnetic wave by converting it into thermal energy. The nanostructuration of materials became a reliable route over the years to enhance the dielectric and magnetic properties, which induce the required interaction. Nanostructured Fe-Co alloys are soft magnetic materials that make them promising candidates for microwave absorption when combined with other materials. The aim of our study was therefore to investigate the microwave absorption properties of based nanocomposites. The nanocomposites were obtained by the solution dispersion method. Nanocrystalline alloys elaborated by mechanical alloying (MA) in a high-energy planetary ball mill (RETSCH PM400) were dispersed into commercial epoxy resin matrix to form thin polymer nanocomposites. The grain size refinement and structural properties changes during milling process were characterized using powder’s X-ray Diffraction (XPERT PRO MPD diffractometer) at different milling durations. XRD spectra analysis show that a grain size refinement of 4.54 nm was reached after 60h milling accompanied with 1.2 % microdeformations. Obtained powders were shaped in small discs for which resonant cavity measurements were undertaken. The based nanocomposites have been subject to an experiment of two-port S parameters measurement in a rectangular waveguide (R120). The microwave experiments involved a Network Analyzer (VNA). Obtained results in terms of reflection losses show a good absorbing characteristic over the [8-15] GHz microwaves band.

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“…The spectrum changes are related to the presence of coarse Fe powder in the epoxy resin matrix: coarse Fe powders are lossy medium with complex relative dielectric permittivity and magnetic permeability [15] and high magnetic properties. Their exposition to the action of the electromagnetic field changes the alignment and rotation of the magnetization spins [16], which modifies the intrinsic properties of the sample.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of Fe-Based Nanocomposites

Otmane¹,

Triaa

Maali³

et al. 2019

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This study reports on the elaboration and characterization of bulk nanocomposites samples obtained by dispersion of metallic powders at the nanoscale as reinforcements in a polymer matrix. Elemental Fe powders were successfully nanostructured via high-energy ball milling. Structural characterization of the produced powders was conducted using X-Ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). The Halder-Wagner approach was adopted to determine the powder’s average grain size, internal strain, lattice parameters and the mixing factors. Structural parameters evolution and morphological changes according to milling progression are discussed. Bulk nanocomposites samples were shaped in a home moulder by dispersion of coarse Fe and nanostructured Fe powders in a continuous matrix of commercial epoxy resin. The obtained bulk samples match the metallic X-band wave-guide WR-90 dimensions used for electromagnetic characterization. The two-port Sij scattering parameters were measured via an Agilent 8791 ES network analyzer. The measured scattering parameters served to calculate the loss factor of samples and to extract the dielectric permittivity via the Nicholson-Ross-Weir conversion. Spectra evolution of the scattering parameters, the loss factor and the dielectric constant for epoxy resin with coarse Fe and nanostructured Fe reinforcements are commented.

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Grain Size Influence on Microwave Absorption Properties in Nanocrystalline Fe<sub>40</sub>Co<sub>60</sub>

Cited by 5 publications

References 14 publications

The Preparation of FeCo/ZnO Composites and Enhancement of Microwave Absorbing Property by Two-Step Method

The Preparation of FeCo/ZnO Composites and Enhancement of Microwave Absorbing Property by Two-Step Method

Microwave Absorption Properties of Fe<sub>40</sub>Co<sub>60</sub> Based Nanocomposites

Synthesis and Characterization of Fe-Based Nanocomposites

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