Synthesis, magnetic and electromagnetic properties of Al2O3/Fe oxides composite-coated polyhedral Fe core–shell nanoparticles

Liu, Xianguo; Sun, Yuping; Feng, Chao; Jin, Chuangui; Li, Weihuo

doi:10.1016/j.apsusc.2013.04.109

Cited by 32 publications

(23 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The NiFe 2 O 4 nanosheets-paraffin composite was prepared by uniformly mixing NiFe 2 O 4 nanosheets with paraffin, as described in detail elsewhere, by pressing them into cylindershaped compacts 16 . Then the compact was cut into toroidal shape with 7.00 mm outer diameter and 3.04 mm inner diameter.…”

Section: Materials Characterizationmentioning

confidence: 99%

Microwave Absorbing Properties of NiFe2O4 Nanosheets Synthesized Via a Simple Surfactant-Assisted Solution Route

et al. 2016

Self Cite

View full text Add to dashboard Cite

NiFe 2 O 4 nanosheets have been synthesized via a simple surfactant-assisted solution route, which are confirmed by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. The NiFe 2 O 4 sample exhibits the sheet-like structure, with width varying from 200 to 800 nm and thickness ranging from 20 to 60 nm. The electromagnetic properties of NiFe 2 O 4 nanosheetsparaffin composites have been deeply investigated. The multiple dielectric relaxation loss in NiFe 2 O 4 nanosheets is attributed to the size distribution and morphology of the NiFe 2 O 4 nanosheets. The magnetic loss in the present system is caused mainly by the natural resonance. An absorber with a thickness of 4.3 mm exhibits an optimal reflection loss (RL) value of -47.1 dB at 7.67 GHz. RL values exceeding -20 dB in the 2.68-17.96 GHz range are obtained by choosing an appropriate absorptionlayer thickness between 1.9 and 10 mm. Not only the RL peak frequency but also the number of the peaks can be well explained by the quarter-wavelength cancellation model.

show abstract

Section: Materials Characterizationmentioning

confidence: 99%

Microwave Absorbing Properties of NiFe2O4 Nanosheets Synthesized Via a Simple Surfactant-Assisted Solution Route

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…The natural frequency at around 14 GHz indicates the enhanced dielectric loss in a limited frequency range. The dielectric loss is sensitive to the absorbing frequency, which becomes the challenge for high technological applications 24 . In addition, it can be found that ε′ and ε′′ for Co(OH) 2 /C nanocomposites exhibit a significant and similar fluctuation, over the 0.03-18 GHz range, ascribed to the displacement current lag at the core/shell interface, similar to the Fe/C and Fe/ZnO nanocapsules 25,26 .…”

Section: Resultsmentioning

confidence: 99%

Synthesis, characterization and microwave dielectric properties of flower - like Co(OH)2/C nanocomposites

Liu

Jin

et al. 2014

Mat. Res.

Self Cite

View full text Add to dashboard Cite

Flower-like Co(OH) 2 /C nanocomposites have been synthesized by a facile hydrothermal method. Flower-like Co(OH) 2 /C nanocomposites were self-assembled by the nanosheets with the thickness distribution of 50-80 nm and abundant flocculent carbon structures. With the help of transmission electron microscopy and energy dispersive spectrometer, nanosheets were observed to have core/ shell structure, in which Co(OH) 2 worked as cores and amorphous C as shells. When the as-prepared products were heated for 6 h at 180 °C, the Co(OH) 2 cores were amorphous. The heating time increased to 10 h, the Co(OH) 2 cores became crystalline. The formation mechanism and the self-assembly evolution process were proposed. The microwave dielectric properties of Co(OH) 2 /C nanocomposites were investigated in the frequency range of 0.03-18 GHz. Compared with the amorphous Co(OH) 2 /C nanocomposites, crystalline nanocomposites had the better conductivity.

show abstract

“…The morphologies of the products were captured using a scanning electron microscope (SEM, JEOL-6300F, Japan) at Paraffin-bonded Ni architecture composites were prepared by uniformly mixing 40 wt.% Ni architectures in the paraffin matrix and by pressing the mixture into cylinder-shaped compacts. More details can be found elsewhere 6,11,12 . The prepared compacts were cut into toroidal samples with 7.00 mm outer diameter and 3.04 mm inner diameter.…”

Section: Methodsmentioning

confidence: 99%

“…More recently, improved high-frequency permeabilities have been observed in magnetic nanomaterials with different morphologies, including polyhedral Fe nanocomposites 11 , FeNi 3 nanorods 12 , dumbbell-like Fe 3 O 4 -Au nanoparticles 5 , hierarchical branch-and flower-like Ni microcrystals 13 and Fe nanoflakes 14 . The improvement in high-frequency permeabilities has been attributed to an increased in their magnetic shape anisotropy.…”

Section: Introductionmentioning

confidence: 99%

“…Among various potential candidates for EM wave absorbers, the one in the form of magnetic nanoparticles core/ dielectric shell-structured nanocapsules, such as Ni/ZnO, FeNi 3 /SiO 2 , Ni/PANI, Ni/C, and Ni/Ni 2 O 3 nanocapsules, has been of particular interest in recent years owing to its tailorable properties in conjunction with smaller sizes and weights [6][7][8][9][10] . An essence of determining the EM wave absorbing properties of the nanocapsules is to obtain a balance between the permeability of the magnetic nanoparticle cores with the permittivity of the dielectric shells 11 . However, the generally low permeability (~ 1) intrinsic in the magnetic nanoparticle cores at gigahertz frequencies, has constrained the strong absorption in some limited frequency range with large variations with absorber thickness.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hydrothermal Synthesis of Three-dimensional Butterfly-like Ni Architectures as Microwave Absorbers

Sun

Cui

et al. 2015

Mat. Res.

Self Cite

View full text Add to dashboard Cite

Three-dimensional butterfly-like Ni architectures were fabricated by a surfactant-assisted hydrothermal method. The Ni architectures, with lengths of about 20 μm and widths of 4-6 μm, were assembled from tens of Ni nanorods with the averaged diameter of about 200 nm. The Ni nanorods were coated by oxide shells. The saturation magnetization of the Ni architectures was found to be 66.2 emu/g. The magnetic loss in the Ni architectures was mainly caused by the natural resonance, while the dielectric relaxation loss was originated from the interfacial relaxation between the oxide shells and the Ni nanorods in addition to the size distribution and morphology of the Ni architectures. Absorbers with a thickness of 2.1 mm exhibited an optimal reflection loss (RL) value of -38.9 dB at 12.8 GHz. RL values exceeding -20 dB in the 8.0-17.8 GHz range were obtained by choosing absorber thicknesses between 1.5 and 3.2 mm. A quarter-wavelength cancellation model was used to explain the observed thickness dependence of RL peak frequency.

show abstract

Synthesis, magnetic and electromagnetic properties of Al2O3/Fe oxides composite-coated polyhedral Fe core–shell nanoparticles

Cited by 32 publications

References 44 publications

Microwave Absorbing Properties of NiFe2O4 Nanosheets Synthesized Via a Simple Surfactant-Assisted Solution Route

Microwave Absorbing Properties of NiFe2O4 Nanosheets Synthesized Via a Simple Surfactant-Assisted Solution Route

Synthesis, characterization and microwave dielectric properties of flower - like Co(OH)2/C nanocomposites

Hydrothermal Synthesis of Three-dimensional Butterfly-like Ni Architectures as Microwave Absorbers

Contact Info

Product

Resources

About