A Study on Microwave Absorption Properties of Carbon Black and Ni0.6Zn0.4Fe2O4 Nanocomposites by Tuning the Matching-Absorbing Layer Structures (original) (raw)
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Advanced Materials Proceedings, 2021
The nano-sized carbon black (NCB) with particle sizes of 15, 25, 55 and 65 nm are added in epoxy matrix in order to investigate the impact of particle sizes on the microwave absorption properties of the nano composites. The NCB powders were characterized by X-ray diffraction and Scanning electron microscopy (SEM) for identification of impurity phases. The complex permittivity spectra were recorded for the composites in the frequency range of 8.2-12.4 GHz. The results revealed that the particle sizes had substantial impact on the electromagnetic properties. On decreasing the particle size, the complex permittivity increases first up to certain extent then decreases. Interestingly, the particle size dependent tangent loss of NCB/epoxy composites shows that 25 nm size is most suited for high loss characteristics, whereas, losses decreases with size < 25 nm, which is attributed to high surface area of the particles. In addition, NCB/epoxy composite with 25 nm particle size illustrated substantial EM absorption efficiency at a frequency of 9.5 GHz, with RL reaching −13.2 dB and reflection loss below −10 dB up to 2.5 GHz with thickness of 2.0 mm. The effect of particle sizes on the electromagnetic properties was also discussed.
Reflectivity of hybrid microwave absorbers based on NiZn ferrite and carbon black
Journal of Aerospace Technology and Management, 2012
This study had as main objective to show that the adequate combination of magnetic and dielectric particles can improve the radar absorbing materials performance. For this, formulations of polyurethane resin loaded with carbon black and NiZn ferrite, with general composition MFe 2 O 4 , where M = Ni, Zn or both elements, homogenized As main result, this study shows that the adequate combination of carbon black and NiZn ferrite improves the processed radar absorbing materials performance due to the adequate adjustment of the impedance matching, which favors the
Journal of Aerospace Technology and Management, 2012
This study had as main objective to show that the adequate combination of magnetic and dielectric particles can improve the radar absorbing materials performance. For this, formulations of polyurethane resin loaded with carbon black and NiZn ferrite, with general composition MFe 2 O 4 , where M = Ni, Zn or both elements, homogenized As main result, this study shows that the adequate combination of carbon black and NiZn ferrite improves the processed radar absorbing materials performance due to the adequate adjustment of the impedance matching, which favors the
Comparison of Microwave Absorption Properties Between BaTiO3/Epoxy and NiFe2O4/Epoxy Composites
Microwave absorption properties of Epoxy/Nickel Fer- rite (NiFe2O4) and Epoxy/Barium Titanate (BaTiO3) composites were investigated and compared in the 1– 14 GHz. Epoxy/filler particles (NiFe2O4 and BaTiO3) composites were prepared with 85/15 mixture ratios via Ultrasonic Probe Sonicator method in solution. The complex permittivity (E0-E00) and permeability (l0-l00) of the composites have been measured at different microwave frequencies in 1–14 GHz via vector network analyzer (Keysight N9926A). The reflection loss (RL) of composites was calculated and evaluated from cam- plex permitivity and permeability. The obtained results show that both composites exhibit the large RL and broadband within the frequency range from 1 to 14 GHz for different thickness. Epoxy/BaTiO3 showed a better microwave absorption at the range of 6–7.2 GHz for 7 and 6 mm, at the range of 7.4–9.1 GHz for 5 mm. However, the Epoxy/NiFe2O4 exhibits the largest RL and the widest bandwidth than those obtained from Epoxy/BaTiO3 composite. POLYM. COMPOS., 00:000–000, 2017. VC 2017 Society of Plastics Engineers
Microwave Absorption Properties of Ni-Zn Ferrite Nano-Particle based Nano Composite
Toroidal shaped sample of particulate composite with 30% (by wt.) Ni-Zn nano-ferrite loaded in polyurethane (PU) matrix has been successfully prepared. Microwave absorption properties of prepared Ni-Zn ferrite based nano composite have been studied. Simulation study for metal backed single layered absorber has been carried for probing the electromagnetic (EM) absorbing properties for different thicknesses of the samples. The vector network analyser (Model PNA E8364B, Software module 85071E) attached with coaxial measurement set up has been utilized to investigate the complex permittivity & permeability. Microwave absorbing properties were investigated by utilizing the measured values of complex permittivity and complex permeability of the absorber in a frequency range of 110 MHz to 18 GHz. Reflection loss (dB) has also been determined for various thicknesses of the composite employing the simulation code. SEM and TGA were performed to analyse the morphological and thermal behaviour ...
Enhanced microwave absorption of La0.7Sr0.3MnO3−δ based composites with added carbon black
Ceramics International, 2014
Composites consisting of carbon black (CB) particles, La 0.7 Sr 0.3 MnO 3 À δ (LSMO) powder, and epoxy resin were prepared for development of a high performance microwave absorber. This study investigated the influence of adding amounts of LSMO powder (60, 70, and 80 wt%) on complex permittivity, complex permeability, and reflection loss for CB (5 wt%)-epoxy composites. The variation of complex permittivity and complex permeability with frequency of the composites was measured by the cavity perturbation technique in the range of 7-14 GHz. It was found that the real part of the complex permittivity increased with increasing LSMO addition and the imaginary part of the complex permeability decreased with increasing frequency. The microwave absorption results indicated that the composite filled with 5 wt% CB particles and 80 wt% LSMO powder had the best absorption performance. The maximum reflection loss was À23.63 dB at 7.87 GHz and the absorbing bandwidth at À10 dB was 1.75 GHz with a matching thickness of 5 mm.
Microwave Absorption Characteristics of some Ferrite-Filled Polymer Composites
Advanced Materials Research, 2014
Prior to their use for microwave absorption, different compositions of NixZn1-xFe2O4 (x = 0.5, 0.6, 0.7 and 0.8) were prepared via mechanical alloying and sintering. X-ray diffractometry (XRD) was used to investigate the crystalline phase formation. Scanning transmission electron microscopy (STEM) and field emission electron microscopy (FeSEM) were used to investigate the particle size and surface morphology respectively. The complex-permeability components, μʹ and μʺ, were also measured using an Agilent 4291B material analyzer from 1 MHz to 1 GHz. From the XRD results it is shown that at 900oC the full phase of nickel zinc ferrite was formed. The μʺ values suggest that the ferrite sample can absorb well microwave energy for frequencies 1 MHz to 1 GHz and higher. This is proved by microwave absorption measurements carried out up to 12 GHz.Keywords: NiZn-ferrite, microwave absorption, magnetic materials
Scientific Reports, 2019
The enhancement of microwave absorbing properties in nickel zinc ferrite (Ni0.5Zn0.5Fe2O4) via multiwall carbon nanotubes (MWCNT) growth is studied in this research work. Ni0.5Zn0.5Fe2O4 was initially synthesized by mechanical alloying followed by sintering at 1200 °C and the microstructural, electromagnetic and microwave characteristics have been scrutinized thoroughly. The sintered powder was then used as a catalyst to grow MWCNT derived from chemical vapor deposition (CVD) method. The sample was mixed with epoxy resin and a hardener for preparation of composites. The composite of multi-walled carbon nanotubes/Ni0.5Zn0.5Fe2O4 shown a maximum reflection loss (RL) of −19.34 dB at the frequency and bandwidth of 8.46 GHz and 1.24 GHz for an absorber thickness of 3 mm for losses less than −10 dB. This acquired result indicates that multi-walled carbon nanotubes/Ni0.5Zn0.5Fe2O4 could be used as a microwave absorber application in X-band.
Journal of Materials Science: Materials in Electronics, 2020
This paper has investigated the absorption properties of multi-layer BaFe 12 O 19/ epoxy composites. Various Ba-ferrites were synthesized by the co-precipitation method followed by high-energy ball milling for the homogenizing and milling purposes. The microstructural, structural, loss-related behavior and magnetic properties were examined by the X-ray diffractometer, field-emission scanning electron spectroscope, network analyzer, and vibrating-sample magnetometer, respectively. The material indicated an enhancement in the saturation magnetization from 35.45 to 57.83 emu/g by increasing the heat-treating temperature (HT). The effects of the type and number of layers on microwave absorption behavior were obtained from the X-range (8 to 12 GHz). The ferromagnetic resonance and transmit-line theories were also employed to analyze these factors on the microwave absorption. These microwave absorbers were modeled and simulated by MATLAB. The simulations were carried out from 8 to 12 GHz to analyze the absorbers performance. Based upon these theories and experimental data, the microwave absorption can be altered solely by changing the materials between the layers. For instance, the maximum peak was increased from − 3 to − 15 dB by altering the as-synthesized ferrite powders to the completed ferrite powders (BaFe 12 O 19). Moreover, there was a sufficient match between experimental data and theoretical results.