Excellent microwave-absorption performances by matched magnetic–dielectric properties in double-shelled Co/C/polyaniline nanocomposites

Abstract

Double-shelled Co/C/polyaniline (Co/C/PA) nanocomposites were prepared by combining the arc-discharge process and in situ chemical oxidative polymerization reaction.

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

“…In addition, the m 00 values present three broad peaks at 2.80, 11.60 and 17.36 GHz, which is ascribed to the 'exchange mode' resonance associated with the small size effect, surface effect and spin-wave excitations. Compared with the reported Ni@C nanocapsules, the present resonance peaks locate at different frequency, which is explained by the fact that resonance frequency is dependent on the particle's radius, lattice defects and interior stress resulting from the core-shell structure [33,34]. For the paraffin bonded Ni@Ce-CeNbC composites, it is worthy noted that the locations of the maximum value and the minimum value on the m 0 curve are qualitatively 'reversal' to those of the ε 0 .…”

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

“…The imaginary part (μ'') has a resonance peak at 3.67 GHz, and the large resonance band is observed in the range of 2-10 GHz. The resonance frequency is dependent on the particle's radius, lattice defects and interior stress resulting from the core-shell structure, which can bring a great increase in the effective anisotropy field and further lead to resonance frequency appearing at a different frequency 4 . The large resonance band may be interpreted as a consequence of size and morphology of the NiFe 2 O 4 nanosheets.…”

“…Therefore, the microwave absorbing materials (MAMs) with the capability of absorbing and attenuating EM energy have become the focus of attention [1][2][3] . MAMs are generally classified into three types: the resistive loss type, the dielectric loss type and magnetic loss type 4 . Single loss type MAMs limits their application in GHz frequencies due to their intrinsic disadvantages.…”

Facile solvothermal synthesis of novel hetero-structured CoNi–CuO composites with excellent microwave absorption performance

“…46 Anisotropy would increase to optimal state with increasing CuO content, which would be greatly helpful to improve electromagnetic waves absorption properties. From 5-18 GHz, the values of C 0 ¼ m 00 (m 0 ) À2 f À1 are nearly constant and this is called the skin-effect criterion, 47 suggesting that the eddy current loss mainly affected the dissipation of microwave energy.…”