Synthesis and microwave-absorbing properties of Co3Fe7@C core–shell nanostructure

Guo, Xiaoguang; Qiao, Xiao Guang; Ren, Qing Guo; Wan, Xiang; Li, Wangchang; Sun, Zhongyue

doi:10.1007/s00339-015-9164-6

Cited by 29 publications

(8 citation statements)

References 36 publications

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“…Taking into account that the Fe-Co metal nominal mass fraction is of 20 wt%, the Fe-Co-based phase corresponds to a 20 wt%. Therefore, the saturation magnetization for the Co 3 Fe 7 phase will be 31.2/0.2 emu/g = 156 emu/g, this value is close to the expected value of 223 emu/g obtained for Co 3 Fe 7 particles with a size of 180 nm [59]. The difference can be ascribed to surface effects due to the smaller particles size, i. e. the superficial spins are usually disordered and have a different magnetic behavior when compared with the spins at the core.…”

Section: Magnetic Properties (Vsm Mzfc and Mfc)supporting

confidence: 85%

Synthesis of Fe2SiO4-Fe7Co3 Nanocomposite Dispersed in the Mesoporous SBA-15: Application as Magnetically Separable Adsorbent

et al. 2020

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The mixture containing alloy and oxide with iron-based phases has shown interesting properties compared to the isolated species and the synergy between the phases has shown positive effect on dye adsorption. This paper describes the synthesis of Fe2SiO4-Fe7Co3-based nanocomposite dispersed in Santa Barbara Amorphous (SBA)-15 and its application in dye adsorption followed by magnetic separation. Thus, it was studied the variation of reduction temperature and amount of hydrogen used in synthesis and the effect of these parameters on the physicochemical properties of the iron and cobalt based oxide/alloy mixture, as well as the methylene blue adsorption capacity. The XRD and Mössbauer results, along with the temperature-programmed reduction (TPR) profiles, confirmed the formation of Fe2SiO4-Fe7Co3-based nanocomposites. Low-angle XRD, N2 isotherms, and TEM images show the formation of the SBA-15 based mesoporous support with a high surface area (640 m2/g). Adsorption tests confirmed that the material reduced at 700 °C using 2% of H2 presented the highest adsorption capacity (49 mg/g). The nanocomposites can be easily separated from the dispersion by applying an external magnetic field. The interaction between the dye and the nanocomposite occurs mainly by π-π interactions and the mixture of the Fe2SiO4 and Fe7Co3 leads to a synergistic effect, which favor the adsorption.

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Section: Magnetic Properties (Vsm Mzfc and Mfc)supporting

confidence: 85%

Synthesis of Fe2SiO4-Fe7Co3 Nanocomposite Dispersed in the Mesoporous SBA-15: Application as Magnetically Separable Adsorbent

et al. 2020

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“…The unitary absorbent is difficult to realize good impedance matching for the reason that most microwave absorbents (such as magnetic materials) have higher permittivity than permeability [4]. Recently, many researchers fabricated the wrapped absorbents composited with magnetic materials and carbon materials to enhance the impedance matching of absorbents, such as CF@carbonyl iron [5], C@FeNi 3 [6], Co 3 Fe 7 @C [7], Fe 3 O 4 @C [8]. These absorbents make use of the respective advantages of magnetic materials with high permeability and carbon materials with relatively low permittivity, which contributes to obtain good impedance matching.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and electromagnetic properties of novel FeNi alloy-coated flake graphite prepared by electroless plating

Liu

Gao

et al. 2016

Journal of Alloys and Compounds

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“…To take an example, some have concentrated on creating insulate shells on the metallic particles in the form of core-shell structures. To know more on this strategy, the interacted reader can refer to FeCo@SnO 2 [15], FeCo@C [16][17][18], Fe@SiO 2 [19][20][21] and Ni@(SiO 2 , TiO 2 ) [22]. There are numerous works on the microwave absorption properties of metallic/(carbon based) composites.…”

Section: Introductionmentioning

confidence: 99%

Tailoring complex permittivity and permeability to enhance microwave absorption properties of FeCo alloy particles through adjusting hydrazine reduction process parameters

Zare

Shams

Jazirehpour

2020

Mater. Res. Express

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Owing to their high permeability, metallic soft magnetic materials exhibit high potential as microwave absorbers. The great challenge in designing desirable absorption properties from these materials is their large electrical permittivity at microwave frequencies. So, decreasing their permittivity within acceptable limits while keeping permeability at sufficiently high or improved levels is considered an important requirement for matching impedance and obtaining excellent electromagnetic (EM) absorption properties. In the present research, FeCo alloy particles produced employing by a simple wet chemical reduction process with the intention of investigating dependence of their EM properties on synthesis parameters. The characterizations were done with the help of x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The intrinsic EM properties (ε r , μ r ) in a frequency range of 2-18 GHz were measured by a vector network analyzer (VNA) for the paraffin composites containing obtained products. The results indicated that the concentration of NaOH and metallic salts as the synthesis precursors can tune the permittivity and permeability. Under optimum conditions, bandwidths of 7.3 and 5.5 GHz with thicknesses of only 1.2 and 1.5 mm were obtained respectively. Also, Reflection loss (RL) of −45 dB was attained. The excellent EM absorption properties demonstrated that the synthesized FeCo alloy may be an ideal absorber having both a wide absorption bandwidth and a low thickness.

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Synthesis and microwave-absorbing properties of Co3Fe7@C core–shell nanostructure

Cited by 29 publications

References 36 publications

Synthesis of Fe2SiO4-Fe7Co3 Nanocomposite Dispersed in the Mesoporous SBA-15: Application as Magnetically Separable Adsorbent

Synthesis of Fe2SiO4-Fe7Co3 Nanocomposite Dispersed in the Mesoporous SBA-15: Application as Magnetically Separable Adsorbent

Fabrication and electromagnetic properties of novel FeNi alloy-coated flake graphite prepared by electroless plating

Tailoring complex permittivity and permeability to enhance microwave absorption properties of FeCo alloy particles through adjusting hydrazine reduction process parameters

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