Lightweight NiFe2O4 with controllable 3D network structure and enhanced microwave absorbing properties

Abstract

3D network structure NiFe2O4 was successfully synthesized by a templated salt precipitation method using PMMA colloid crystal as templates. The morphology, phase composition and microwave absorbing properties of as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vector network analyzer (VNA), and so on. The results revealed that the 3D network structure was configurated with smooth spherical walls composed of NiFe2O4 nanocrystals and their pore diameters being in the range of 80–250 nm. The microwave absorption properties of the 3D network structure NiFe2O4 were crucially determined by the special structure. The synergy of intrinsic magnetic loss of magnetic NiFe2O4 and the interfacial polarization enhanced by 3D network structure and the interaction of multiple mechanisms endowed the sample with the feature of strong absorption, broad bandwidth and lightweight. There is more than one valley in the reflection loss curves and the maximum reflection loss is 27.5 dB with a bandwidth of 4 GHz. Moreover, the 3D network structure NiFe2O4 show a greater reflection loss with the same thickness comparing to the ordinary NiFe2O4 nanoparticles, which could achieve the feature of lightweight of the microwave absorbing materials.

Ordered mesoporous NiFe2O4 with ultrathin framework for low-ppb toluene sensing

“…Recently, ordered mesoporous metal oxides such as SnO 2 [24,25], In 2 O 3 [26][27][28][29], Cr 2 O 3 [30,31], NiO [32][33][34], Co 3 O 4 [35,36], ZnO [37,38], WO 3 [39][40][41], have widely been investigated as semiconducting gas-sensing materials since their large specific surface area and ordered porous structure allows for the improved sensing performance [42]. Nickel ferrite (NiFe 2 O 4 ) is one of the well-known spinel-type semiconductors and could find application in wide fields including gas sensor [43][44][45], catalysis [46][47][48], magnetism [49][50][51], and so on. Although some ordered mesoporous NiFe 2 O 4 materials have been synthesized in previous literature [52][53][54], investigation on their potential applications is still very limited.…”

Economical synthesis of composites of FeNi alloy nanoparticles evenly dispersed in two-dimensional reduced graphene oxide as thin and effective electromagnetic wave absorbers

“… 12–15 As is well known, the EM wave absorption performance of a material is determined by complex permittivity, complex permeability and impedance matching, which are affected by its components, microstructure, size and so on. 16,17 Hence, by rational cooperation of the magnetic components (Fe 3 O 4 , 18,19 Fe, 20,21 Co, 22 Ni, 23 NiCo 2 , 24 NiFe 2 O 4 25 ) and carbon-based materials (carbon nanotubes, 26 carbon fiber, 27 graphene, 28 porous carbon materials 29 ) within the magnetic/carbon-based hybrids, competent EM wave absorbers can be achieved.…”

Effect of Nickel-spinal-Ferrites on EMI shielding properties of polystyrene/polyaniline blend

“…Blends of Nickel spinel ferrites (NiFe) NiFe 2 O 4 and polymethyl methacrylate (PMMA) crystals were made as 3D network structure 80-250 nm Pore diameter for EMI shielding purpose through salt precipitation method. This network structure has greater reflection loss as compared to NiFe nanoparticles with the lightweight property as EMI shielding materials [18]. Barium ferrite and graphite were incorporated into PANI to make a conductive composite for EMI shielding purpose which shows shielding effectiveness (− 37.1 dB) in X-band (8.2-12.4 GHz) range depends on dielectric loss [1].…”

“…S6 gave SR T of less than − 35 dB in the broad range of frequency of 0.1-20 GHz in which SE T values dropped even below to − 45 dB in 10-14 GHz frequency range. − 10 dB is the threshold value for a good EMI shielding film, for polymeric composite, this value is achieved with very high filler loadings 30-40 wt% of fillers and then get SE T value in range of − 10 to − 20 dB and high shielding effectiveness of less than − 30 dB with filler loading odd 50-70 wt% or from pure conductive/magnetic materials[18,27,28].According to EMI shielding theory, the EM wave reflects back when it falls on the electrically conductive surface and absorbed when falls on magnetic surface, both PANI and NiFe particles are dispersed inside the PS matrix and outer most surface mostly consisted of non-conductive PS. SE R is not very high indicating that most of the EM wave…”