Ferrite Composites Research Articles

Effect of Bismuth Oxide on the Structure, Electrical Resistance and Magnetization of Lithium Zinc Ferrite

The structural, electrical, and magnetic properties of lithium zinc ferrite prepared by ceramic technology have been studied. The composition of lithium zinc ferrite is Li0.4Fe2.4Zn0.2O4 with 1 and 2 wt % bismuth oxide. The addition of Bi2O3 prior to sintering of the samples has been shown to affect the structural, electrical, and magnetic properties of the ferrite. A significant increase in density from 4.47 to 4.65 g/cm3 and a decrease in porosity from 4.8 to 2.3% have been observed when the concentration of bismuth oxide has been increased to 2 wt %. The Bi2O3-containing samples have higher specific electrical resistivity compared to that of the additive-free lithium zinc ferrite. The introduction of bismuth oxide has reduced the specific saturation magnetization from 70.55 to 54.76 G cm3/g. The Curie temperature has not changed significantly. An optimal combination of macroscopic properties of ferrite has been found at 1 wt % Bi2O3 concentration.

Engineering hard ferrite composites by combining nanostructuring and Al3+ Substitution: From nano to dense bulk magnets

We have investigated the bottom-up sol-gel synthesis of nanocomposite powders comprising two magnetic phases (hexagonal Sr ferrite and spinel Co ferrite) in order to outline a strategy to obtain permanent magnets with large coercivities via low-cost and scalable syntheses. The correlation between morphological, structural and macroscopic magnetic properties of Al-substituted SrFe12O19 and SrFe12O19/CoFe2O4 nanocomposites was analyzed in detail. The hysteretic behavior can be tuned by cation substitution and/or modulation of the super-exchange coupling at the interface of the constituting phases. The magnetic data, supported by Monte Carlo simulations, indicates enhanced magnetic coupling within the composite: this observation underscores the significance of soft crystallite size and epitaxial growth quality at the interface as key factors influencing super-exchange coupling strength, ranging from fully coupled to essentially decoupled composites. Bulk magnets with high density were manufactured by compacting these nanostructured phases using spark plasma sintering, without an applied magnetic field. Consolidation of powders significantly impacted magnetic properties, by increasing remanent magnetization and decreasing coercivity due to enhanced super-exchange coupling. The presence of two phases hindered reciprocal growth, influencing coercivity differently in various compositions. Overall, the compaction enhanced magnet performance through improved particle alignment and super-exchange coupling, offering the potential for optimized magnet design.

SYNTHESIS AND PHYSICO-CHEMICAL PROPERTIES OF A NEW COMPLEX FERRITE

The article discusses the synthesis of new complex ferrite, radiographic and electron microscopic studies. The phase of complex ferrites was synthesized by the method of high-temperature sol-gel synthesis. For the first time, the structure of CrKFe2O5 Composite ferrite was studied by X-ray phase analysis and scanning electron microscope methods, the syngony type, elementary cell parameters, radiographic and pycnometric densities, and elemental analysis were determined. A comparative analysis of the relationship between the parameters of the Crystal cell of primary substances and the parameters of the obtained complex ferrite Crystal cell was carried out. Micro-samples were taken from different parts of the crystallite obtained through a scanning electron microscope, the elemental composition of the crystals was analyzed, and the general type of layer of the complex ferrite surface was demonstrated. As a result, the fact that the compound consists of two phases, the clarity of its construction was determined by the topography and chemical composition of the compound. As a result, it was found that the newly synthesized complex ferrite corresponds to the Formula CrKFe2O5. The particle size of the compounds formed is large (between 200 μm, 20.0 μm, 5.00 μm and 2.00 μm).

Synthesis and characterization of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrite composites for antenna applications

A series of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrites (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were successfully synthesized by one-pot coprecipitation route. XRD analysis reveals the formation of Ba2Zn2Fe12O22 and NiFe2O4 composite after sintering calcined precursor powder at 1200 °C/4 h. Densification behaviour was evaluated by Archimedes’ principle. Field emission scanning electron microscopy was used to study morphological characteristics. Room temperature magnetization behaviour was evaluated using a vibrating sample magnetometer. In composite, it was observed that the saturation magnetization (Ms) and coercivity (Hc) increased with increasing NiF content. With the increase of NiF in the composite, the permittivity (ε) decreased from 28.6 (for x = 0.2) to 13.6 (for x = 0.8) with the corresponding decrease in dielectric loss (tanδε) at 100 MHz. The permeability (μ) also decreased from 21.3 (x = 0.2) to 17.9 (x = 0.8) with the associated decrease of the magnetic losses (tanδμ) at 100 MHz. Miniaturization factor (n) of 19.2 and characteristic impedance of 1.1 were obtained for x = 0.4 composition at 100 MHz along with low dielectric loss factor (tan δε/ε) and magnetic loss factor (tan δµ/µ). The ferrite resonator antenna was fabricated using FR4 as substrate and ferrite pellet as magneto-dielectric resonator material. The antenna characteristics parameters reflection loss S (1,1) and voltage standing wave ratio (VSWR) were measured by vector network analyser (VNA).

Microstructural, dielectric, electrical, electromagnetic, and magnetic property enhancements in GdIG /TrIG/ Mn0.2Co0.3Zn0.5Fe2O4 ferrites composites for electronic devices application

Gadolinium garnet ferrite (GdIG) and terbium garnet ferrite (TrIG), known for their favourable magnetic and dielectric characteristics, were combined with doped zinc spinel ferrite (GdIG)x-(TrIG)y/Mn0.2Co0.3Zn0.5Fe2O4(1-x-y) (at x=1 y=0, x=0 y=1, x=y=0.5, x=y=0.25, x=y=0) to achieve improved permittivity, permeability and magnetic properties with reduced magneto-dielectric losses. Our study details the synthesis process and the resulting enhancements in structural, magnetic, and dielectric properties of the prepared samples. Analysis of the X-ray diffraction (XRD) patterns confirmed the presence of a crystalline structure characterized by both cubic spinel and cubic garnet phases in the composites. The microstructures of the composites were analysed with field emission scanning electron microscopy (FESEM), revealing the variation in a grain size from 0.11 μm to 0.96 μm at x =y=0.5. A thorough link between the crystal structure and XRD spectra, transmission electron microscope (TEM), and selected area electron diffraction (SAED) patterns have all been investigated in order to enhance the characterisation of the samples. At 1KHz, the composites exhibit highest electrical resistivity values of 5.9×106 Ωm and 2.6×106 Ωm. With the incorporation of spinel ferrites in garnet ferrite composite (x=y=0.25) the highest value of dielectric constant (885.2) and low value of dielectric loss (0.07) at 100 KHz has been obtained. Permeability values, derived from permittivity data, showed an increase in real permeability values of from 1.4×1012 to 9.2×1017 for x=y=0.5 to x=y=0.25 composite. Vibrating sample magnetometer (VSM) further confirm that the composite x=y=0.25 has highest magnetic saturation (148.8 emu/g), coercivity (502 Oe) and microwave operating frequency (33.6 GHz). The observed high dielectric constant, low loss values, switching field distribution and good magnetic properties suggest the potential suitability of these samples for various electronic devices like: high frequency devices, antennas, switching devices and magnetic recording devices.

The potential of Gd doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

The study shows that the addition of gadolinium ions has a significant impact on the structure, morphology, and adsorption properties of Ni-Co spinel ferrite that was synthesized by the sol-gel auto-combustion method. The research also indicates that the higher the Gd content, the greater the increase in the lattice parameter, which suggests that Gd3+ ions uniformly replaced the octahedral Fe3+ ions. The morphology and chemical composition of Gd-doped Ni-Co ferrites have been studied using SEM and EDS. Gd adding to the NiCoFe matrix increases the BET surface area by 50% (from 48 to 72 m2/g) and promotes the formation of mesopores with an average radius from 3.9 to 4.9nm. The pHPZC values of Gd-doped ferrites are in the range of 7.22-7.39, which means that the ferrite surface will acquire a positive charge at natural pH, so this will promote the adsorption of Congo red anionic dye through electrostatic interaction forces. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to explain the mechanism of CR adsorption on the Ni0.5Co0.5GdxFe2-xO4 adsorbent surface. The ionic-covalent parameter has been estimated to describe the surface acid-base properties. Overall, this study highlights the potential of Gd3+ doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

Effect of sodium dodecyl sulfate on the dielectric and electrical properties of poly (vinylidene fluoride)-zinc ferrite composites

Polymer composites comprising Poly (vinylidene fluoride) (PVDF) as a matrix, Zinc Ferrite (ZnFe2O4: ZFO) as ceramic filler and Sodium Dodecyl Sulfate (SDS) as a surface modifying agent have been synthesized through a simple solvent casting route for application in energy storage devices. The Scanning Electron Microscopic (SEM) study confirmed that the surface modification through Sodium Dodecyl Sulphate improved the dispersion of ZFO particles in the PVDF matrix. The FTIR Spectrophotometer study revealed the existence of expected functional groups in the modified composites The advantage of treatment of SDS on the composite obtained from blending of PVDF with Zinc Ferrite was investigated. The Impedance Analyzer study indicated that the composite with 1.5 wt.% Zinc Ferrite nanoparticles encapsulated by SDS exhibited the highest dielectric constant and reduced loss tangent. In addition, the experimental values of the dielectric constant were compared with some theoretical models. Further, the PE loop study showed higher remanent polarisation in the 1.5 wt.% SDS treated composite indicating that treatment of SDS on Zinc Ferrite (ZFO) can be adopted to fabricate composites for high energy storage applications.

Effect of Zr, Sm and Gd Doped CoFe2O4 on Structural, Spectral and Magnetic Properties

In this work, cobalt composite nano ferrites with chemical formula CoZr0.05-xRExFe1.95O4 (x = 0 and 0.025 and RE = Sm, Gd) were prepared using sol-gel synthesis method and studied structural, optical and magnetic properties of them. The Rietveld assessment of XRD data validated the emergence of a single-phase cubic spinel configuration for all compounds. SEM has been used to study the surface morphology of the compounds. Energy gap has been estimated and the values are 2 eV, 1.8 eV and 1.6 eV for CoZr0.05Fe2O4, CoZr0.025Sm0.025 Fe1.95O4, and CoZr0.025Gd0.025 Fe1.95O4 compounds respectively. FTIR and Raman spectra confirmed the structure with the appearance of standard modes. The RE replacement in CoFe2O4 ferrites has an intense impact on magnetic properties. With the substitution of Sm3+ and Gd3+ ions in cobalt-zirconium ferrite, there is a reduction in saturation magnetization (55 emu g−1 of CoZr0.05Fe2O4 reduced to 25 emu g−1 for Gd3+ and to 29 emu gm−1 for Sm3+) as the size of crystallites decreases. A decrease in crystallite size correlates with an increase in the number of spin disorder occurrences in rare Earth-substituted cobalt-zirconium ferrite nanoparticles Further, the decrease in coercivity (2440 Oe of CoZr0.05Fe2O4 reduced to 720 Oe for Gd3+ and to 29 Oe for Sm3+ with rare Earth element doping is due to the crystallite size and large lattice distortion showed an enhancement of magnetocrystalline anisotropy field which effects a shift of resonance frequencies from higher frequencies which is good for the memory storage devices.

Modulated magnetostriction and multiferroic properties in the PVDF-based cobalt ferrite particulate composites

Multiferroic materials (MFM) have drawn substantial attention for developing smart magnetodielectric devices. Herein, cobalt ferrite CoFe2O4 (CFO) was synthesized by a glycine–nitrate sol-gel auto-combustion route and, PVDF-based particulate composite films embedded with CFO have been developed. A comprehensive investigation evaluated the effects of magnetostriction, initiated from the embedded CFO phase, on magnetodielectric characteristics of composite films. The structural, electrical, magnetostrictive and magnetodielectric properties were investigated. The embedded CFO particulate endows PVDF matrix at a higher β–phase forming ability, which enhances the ferroelectricity with a polarisation (Pmax∼1.09 μC/cm2@ 850 kV/cm), a higher dielectric constant (εr∼12.33) and lower dielectric loss. The typical magnetic hysteresis loop was obtained with saturation magnetization (MS∼4.96 emu/g) and coercivity (HC∼1.49 kOe), revealing the ferromagnetic ordering in composite films. The response of the magnetodielectric (MD) is observed at room temperature, that is, a large negative MD coefficient ∼2.1 % @ Hcr∼5.0 kOe is achieved for Co0.9Fe2.1O4/PVDF composite films, while MD∼0.65 %@ Hcr∼1.0 kOe is obtained for Co1.1Fe1.9O4/PVDF films, accompanied by a maximum MD∼4.35 % at resonance frequency. The variation in the MD performance reveals a close correlation to the modulated magnetostriction, such as the magnetocrystalline anisotropy, field-induced coefficient and magnetostrictive susceptibility, indicating the strain-mediated coupling MD effect. The multiferroic properties in CoxFe3–xO4/PVDF composites have potential for magneto-dielectric sensing applications. Furthermore, this work would be exploited to understand MD coupling mechanism and develop MFM for multifunctional devices.

Ultrafast solid-state microwave fabrication of CoFe2O4@carbon black composite with coupling reinforcement effect towards actualizing effective water decontamination

Due to the synergistic redox coupling between the two metals, cobalt ferrite-based materials demonstrate stable degradation properties for organic pollutants by activating peroxomonosulfate (PMS). However, the challenge lies in developing the simplest and fastest methods to construct and modulate cobalt ferrite composites. In this study, CoFe2O4 nanoparticle-integrated carbon black composite catalysts (CoFe2O4-CB-x) were prepared using an environmentally friendly solid-state microwave method. The CoFe2O4-CB-120 catalyst showed excellent efficiency in degrading tetracycline (TC) through PMS activation, achieving a removal rate of nearly 90 % in 30 min with an apparent rate constant of 0.1232 min−1. The catalyst also effectively degraded various organic compounds and real-life wastewater by almost 80 %, promising application potential. Furthermore, CoFe2O4-CB-120 maintained its high activity after five cycles, attributed to its its magnetic properties facilitating good separation and preventing catalyst loss during cycling tests. The degradation mechanism of the CoFe2O4-CB-120/PMS system was thoroughly investigated, identifying key active species such as SO4•−, •OH, and 1O2, with proposed pathways for TC degradation. This study presents an innovative, simple, and efficient strategy for producing spinel cobalt ferrite and carbon composites for PMS activation in organic pollutant degradation.

Study on the high resistivity and resonant frequency characteristics of Eu-doped NiZnCo ferrites

To fulfill the urgent demand for materials suitable for contemporary high-frequency applications, Eu-substituted Ni0.55Zn0.35Co0.1EuxFe2-xO4 (NZCEF, 0 ≤ x ≤ 0.10) composite ferrites were successfully synthesized by a solid-state reaction method, demonstrating characteristics apt for high-frequency functionalities. Detailed examination via SEM and EDS confirmed the compositional purity of these ferrites. Microstructural analysis indicates that the incorporation of europium results in a reduction of the average grain size in NZCEF composites, enhancing the material's densification. Measurements of resistivity and dielectric properties reveal that Eu doping affects the concentration of Fe2+ and Fe3+ ions as well as lattice defects within the ferrite, thereby leading to higher dielectric constants and resistivity (ρ, 6.51 × 108 Ω m). Magnetic analysis confirms that the substitution with Eu ions significantly increases both the coercivity and the ferromagnetic resonance frequency (fr), from 25.7 Oe and 445 MHz to 45.73 Oe and 1.22 GHz, respectively. This improvement is attributed to changes in grain size and domain wall motion. Consequently, Eu3+-substituted NZCEF ferrites exhibit superior electromagnetic properties, making them ideal candidates for advanced high-frequency material applications.

Facile single-step synthesis of ZnFe2O4@biochar for synergistic adsorption and photo-Fenton degradation of RB and RBR binary dyes

BackgroundBiochar ferrite composites have attracted widespread interest in adsorption and photocatalysis. MethodsZnFe2O4@biochar (ZnFe2O4@C) photo-Fenton catalyst was synthesized by single-step pyrolysis strategy and characterized by SEM-EDS, FT-IR, XRD, BET, XPS, VSM, UV–vis DRS. The activity of ZnFe2O4@C was investigated via rhodamine B (RB) and reactive brilliant red X-3B (RBR) binary dyes photo-Fenton degradation. Significant FindingsZnFe2O4 was uniformly anchored on biochar and formed magnet-separable ZnFe2O4@C. ZnFe2O4@C exhibited synergistic adsorption and photo-Fenton activity. Combination ZnFe2O4 with biochar reduced the recombination rate of photo-generated carriers, and effectively accelerated the degradation of RB and RBR binary dyes. Under the optimal conditions, the removal efficiency of RB and RBR were both more than 99.00%, and the reaction rate constants were 0.1276 min–1 and 0.0928 min–1, respectively. The photo-generated holes and •OH were the main active species. The possible degradation pathways were involved in cleavage of C–N, N-de-ethylation, chromophore cleavage and benzene ring opening for RB, and deionization, cleavage of N = N and C–N, oxidization and benzene ring opening for RBR. This work provided a facile single-step synthesis strategy for ZnFe2O4@biochar photo-Fenton catalyst, which was magnet-separable, environment-friendly, pH adaptability-widely, and there was the potentiality for organic dyes wastewater treatment.

Nonlinear and Optical Limiting Properties of Graphene‐Ferrite Nanocomposites: A Review

With a specific focus on graphene‐ferrite nanocomposites, this comprehensive review provides insight into their nonlinear and optical limiting features. The intriguing combination of graphene electronic structure and the versatility of ferrites results in a diverse range of composites materials with exceptional properties. This unique synergy opens up numerous practical applications across different sectors. The review paper, which primarily focuses on recent advances in research, delves into the structural characteristics and attributes of these hybrids, highlighting their behaviour in nonlinear refraction, nonlinear absorption and optical limiting. Further, the explorations of cutting edge strategies for the development of wavelength and intensity dependent optical limiters are detailed. Additionally, there view paper emphasizes the challenges that still need to be overcome to fully utilise graphene‐ ferrite composites in nonlinear optical process and optical limiting.This article is protected by copyright. All rights reserved.

Improved magnetic, electrical, and dielectric characteristics of graphene nano-platelets (GNPs)-Integrated Ni0·4Cd0·6Fe1.97Sm0.03O4 ferrite composites synthesized via sol-gel auto-combustion method

This research work analyzes the impact of graphene nanoplatelets (GNPs) on the structural, electrical, dielectric, optical, and magnetic properties of the Ni0·4Cd0·6Fe1.97Sm0.03O4/x-GNPs (SNCF/GNPs) composites (x = 0 %, 2.5 %, and 5 %) prepared via the sol-gel auto-combustion route. The results revealed that SNCF particles were distributed on GNPs which improved the multifaceted properties of SNCF spinel ferrites. XRD analysis confirmed the FCC spinel structure with a minimum crystallite size (D) of 18.99 nm for sample with 5 wt %GNPs. The DC electrical resistivity decreased from 9.06 × 1011 Ω-cm at 313K to 1.41 × 108 Ω-cm at 673K, revealing the semi-conducting nature of composites. The improved electroconductivity and reduced bandgap energy are observed for samples with minimum resistivity 1.02 × 105 Ω-cm at 673K and 1.70 eV energy, respectively, containing 5 wt %GNPs. Samples show higher permittivity values at low frequency and decreased at high frequency. The maximum ac conductivity is observed for composite with 5 wt %GNPs which is attributed to the hopping mechanism. Finally, the magnetization (Ms) increased from 52.24 to 79.71 emu/g with increasing GNPs contents. Hence, the synthesized composites with 5 wt %GNPs are more favorable than the pure sample for application in waste-water treatment, high-frequency devices, and energy storage devices.

The enhanced electromagnetic shielding effect in the design and simulation of NFC antenna employing optimized NiCuZn ferrite composition with improved magneto-dielectric properties and low-temperature sintering characteristics

In this study, a novel NiCuZn (Ni0.24Cu0.21Zn0.55BixFe2-xO4 (x = 0,0.025, 0.050, 0.075)) ferrite composition (Ni/Zn molar ratio is 24/55) was successfully prepared by the addition of Bi3+ ion for substitution. It is demonstrated that Bi2O3 served as an effective doping agent to reduce the sintering temperature to 900 °C and enhanced the high-frequency magneto-dielectric properties. Notably, the maximum permeability is ∼118 (@ 13.56 MHz) when x = 0.050 with a cut-off frequency of 47 MHz, which is nearly four times higher than that of the unsubstituted sample. In addition, an NFC antenna employing optimized ferrite as an electromagnetic shield sheet was designed and simulated. The results indicated that the chaotic and weakened magnetic field was recovered, and the biased resonant frequency was restored from 31.87 MHz to 13.68 MHz. These findings hold significant scientific importance and practical value in achieving superior electromagnetic shielding performance and miniaturization in NFC system.

Enhancing X-band microwave absorption properties with nickel ferrite and carbon-based composites

The present study focuses on synthesizing a composite material comprising of nickel ferrite and carbon derived from cotton, to exhibit exceptional microwave absorption capabilities over a wide frequency range. By adopting a mechanical alloy method, the microwave-absorbing composite is developed. The microwave absorption characteristics of the developed composites are further unearthly in terms of their permittivity and permeability. Combining magnetic and dielectric phases produces better eddy current loss and polarization, which are primarily responsible for absorption characteristics. The developed composites are cast into rectangular pallets to evaluate microwave absorption characteristics and examined using a vector network analyzer within the 8.2–12.4 GHz frequency range. With a pallet thickness of 2.55 mm, the entire X-band frequency is effectively covered, yielding a remarkable minimum reflection loss of −20.46 dB at 10.01 GHz. The current work's findings, owing to the synergistic combination of nickel ferrite and carbonized carbon provide a practical approach for developing a hybrid material with remarkable electromagnetic performance.

Ce3+ doped zinc manganese ferrite nanoparticles: Tuned mechanical, dielectric and radiation shielding characteristics

In this paper, the impact of cerium (Ce) additives on the structural, electrical and radiation attenuation characteristics of cerium zinc (Zn)- manganese (Mn)-based spinel nanoferrite, named ZMCeF-nanoferrite was investigated. Our investigation involved a thorough examination of the morphology and distribution of the ZMCeF-nanoferrite utilizing HR-TEM analysis, which revealed showcasing the distinctive spherical morphology of the nanoparticles along with observations of their aggregation tendencies. These findings are ascribed to the heightened magnetic interactions between the ZMCeF-ferrite nanoparticles. The ZMCeF5 nanoferrite demonstrates an optimal dielectric constant value compared to the free Ce ferrite composition, exhibiting an enhancement ratio of 109 %. Additionally, it showcases optimal conductivity, with an upgrading ratio of 780 %, and minimal loss, with an enhancing ratio of 3.5 %. Moreover, the elastic moduli of the ZMCeF5 sample exhibited a marked increase as the Ce content increased. Upon examining the mass attenuation coefficient (MAC) of ZMCeF-nanoferrite across three energy regions, we note a trend of increased MAC values corresponding to higher Ce additions. In contrast, the half-value layer (HVL) values decrease as Ce additions increase. Comparing the HVL values of the current ZMCeF-nanoferrite with those of selected radiation shielding material, we find that HVL of the ZMCeF-nanoferrite exhibits smaller values. These findings present promising prospects for optimizing spinel nanomaterials for use in radiation shielding applications.

Investigation in the Influence of the Composition of Metal Ferrite Based Composites on the Dielectric Constant Through Response Surface Methodology

Investigation in the Influence of the Composition of Metal Ferrite Based Composites on the Dielectric Constant Through Response Surface Methodology

Constructing and optimizing epoxy resin-based carbon Nanotube/Barium ferrite microwave absorbing coating system

High-performance microwave absorbing coatings are highly indispensable for protecting human health and enhancing military strength. A single- and double-layer wave-absorbing coating system that employs complex microwave absorbers composed of the helical carbon nanotubes/doped barium ferrite composite with epoxy resin as the matrix was developed. The concentration and thickness of the coating were optimized by the numerical simulation and the adaptive genetic algorithm. The developed helical carbon nanotubes/doped barium ferrite wave-absorbing composites have a porous reticular structure, with abundant microscopic cavities and an adequately conductive network. The coatings are characterized by a flat surface, good uniformity, and high density. The reflectivity measured by the arch method is similar to that obtained through the finite element simulation, where the absorption bands of all the developed coatings are distributed in the range of 10–18 GHz. The optimized wave-absorbing coating exhibits the most uniform scattering pattern, the largest radar cross section (RCS) reduction, the smallest input reflection coefficient, and the highest absorptivity. Thus, it exhibits the best comprehensive microwave-absorption performance with a minimum reflection loss of −17.22 dB at 16.66 GHz. In particular, the absorption bandwidth of the coating can reach 9.16 GHz, which is attributable to its multiple synergistic electromagnetic attenuation mechanisms and its excellent characteristics of interference-cancellation and impedance-matching characteristics. Generally, helical carbon nanotubes/doped barium ferrite wave-absorbing coatings are promising candidates for applications in Ku-band microwave absorption.

Microwave-Assisted Catalytic Deconstruction of Plastics Waste into Nanostructured Carbon and Hydrogen Fuel Using Composite Magnetic Ferrite Catalysts

Microwave-Assisted Catalytic Deconstruction of Plastics Waste into Nanostructured Carbon and Hydrogen Fuel Using Composite Magnetic Ferrite Catalysts