Microwave Absorption Research Articles

Polypyrrole nanoclips-coated Co/C nanostructures with enhanced microwave absorption

There is a challenge to boost the electromagnetic wave absorption performance of magnetic carbon-based materials by rationally adjusting the structure of MOF. In this paper, nanoclip-shaped polypyrrole (PPy) was wrapped on the surface of the Co/C nanoparticle derived from Co-MOF via in-situ polymerization of pyrrole with the help of cetylammonium bromide. The electromagnetic parameters of prepared Co/C@PPy can be easily tuned by adjusting the feed ratio of PPy to Co/C. The optimum value of reflection loss (RL) for Co/C@PPy is −45.49 dB at 2.4 mm and 15.12 GHz when the feed ratio of pyrrole to Co/C is 200 μL to 80 mg, and the effective absorption bandwidth (EAB, RL ≤ −10 dB) reaches 5.97 GHz (11.76–17.73 GHz) at the matching thickness of 2.5 mm. This study paves the way for further design and preparation of the nanocomposites based on MOF-derived nanostructures with excellent EMW absorption performance.

Heterointerface engineering of CoO/Co with ordered carbon for synergistic magnetoelectric coupling to enhance wideband microwave absorption

Highly developed electronic information technology has undoubtedly resulted in numerous benefits to the military and public life. However, the resulting electromagnetic wave (EW) pollution cannot be ignored. Therefore, the application of highly efficient EW materials is becoming an important requirement. In this study, magnetic-dielectric heterointerface strategy was applied to construct absorbers with desirable electromagnetic wave properties. A novel CoO/Co nanoparticle anchored to N-doped mesoporous carbon (CoO/Co/N-CMK-3) composites was fabricated by facile precipitation reaction and the electromagnetic characteristics have been well optimized by adjusting pyrolysis temperature. The CoO/Co/N-CMK-3 yielded its highest performance at an annealing temperature of 800 °C, with an extended effective absorption bandwidth of 5.83 GHz and unusually low minimum reflection loss of−63.82 dB, even at a thickness of just 1.8 mm and low filler loading (10 %). For the excellent microwave absorption property, the advantages of the CoO/Co/N-CMK-3 can be summed up as follows. Firstly, the incorporation of heterointerfaces among N-CMK-3, CoO, and Co introduces abundant polarization centers, triggering various polarization effects and increasing dielectric losses. Secondly, the CoO/Co magnetic component introduced the strong magnetic loss and improved the impedance matching capability of CoO/Co/N-CMK-3. Thirdly, the extraordinary magnetic-dielectric behavior is supported by multiple magnetic coupling networks and enriched air-material heterointerfaces, boosted the magnetoelectric cooperative loss for further optimizing the electromagnetic dissipation and broadening the effective absorption frequency band. Moreover, the CST simulation results validate the impressive operational bandwidth and reflection loss characteristics of the obtained absorbers. This study demonstrates a novel heterointerface engineering strategy for designing lightweight, wide-band, and high-performance EW absorbers.

Enhanced microwave absorption in Fe3O4@PS/MWCNT multicomponent composites: Fabrication, characterization, and performance analysis

Multiple-component materials with advanced microstructure are increasingly utilized in the development of microwave absorption materials. In this paper, a magnetic hollow sphere composed of Fe3O4@PS was fabricated by simply depositing Fe3O4 nanoparticles onto the surface-modified PS hollow spheres through electrostatic interactions. The microwave absorption properties of Fe3O4 @PS hollow spheres were studied by varying the loading capacity of Fe3O4. The results show that when the Fe3O4 content is 28.59 wt%, the optimal minimum reflection loss is −26.9 dB with effective absorption bandwidths (RL ≤ −10 dB) exceeding 0.3 GHz. Furthermore, the straightforward combination of the Fe3O4@PS with MWCNTs enables the enhancement of the microwave absorption up to −41.4 dB at 14.5 GHz, with an effective absorption bandwidth exceeding 5.9 GHz (12.1–18 GHz) at a thickness of 2 mm. This study is expected to provide valuable insights into the design of nanocomposites for microwave absorption applications.

Enhancement of Microwave Absorption Properties of Crystal‐Engineered Perovskite Oxide Using Cobalt Ferrite

A multiferroic composite that comprises of a non‐ferromagnetic ferroelectric material with a high dielectric constant and a non‐ferroelectric ferromagnetic material with a high magnetostriction is of tremendous interest as microwave absorption material due to its applicability in tunable microwave phase shifters, resonators, filters, absorbers, etc. In the previous work, the solid solution of strontium titanate and sodium bismuth titanate (Sr0.5(Na0.5Bi0.5)0.5TiO3, SNBT50), which is observed to possess a very high dielectric constant at room temperature (Ferroelectrics, Vol 583, 252–263 [2021]), is successfully reported. Thus, in this work, a core–shell magnetoelectric composite is prepared by coating highly ferromagnetic and magnetostrictive cobalt ferrite onto a diamagnetic but strongly ferroelectric SNBT50 to enhance its magnetic properties and to investigate the modification in microwave absorption. Detailed characterization of electric and magnetic parameters in microwave frequency range (1–20 GHz) reports substantial enhancement in the magnetic permeabilities as well as the magnetic loss of the composite system, as opposed to bare SNBT50. This results in improved impedance matching in the system and enhanced microwave absorption, with a minimum reflection loss (RL) of −20.19 dB and an increased effective absorption bandwidth of 4.56 GHz at a mere 2.7 mm absorber length. Consequently, in this investigation, a promising pathway is established for the development of multiferroic composites with favorable magnetoelectric coupling at room temperature that possesses wide absorption bandwidth and suitable RL, making them highly suitable for use in multiferroic‐based microwave components.

Ultra‐Broadband and Reconfigurable Liquid‐Based Microwave Metasurface Absorber

Liquids, with their advantages of fluidity, ease of shaping, and tunability, have exhibited promising potential in the creation of reconfigurable metamaterials (MMs). Water, being the ubiquitous liquid and cost‐effective resource on Earth, has been utilized for the construction of liquid‐based microwave metasurface absorber (MSA). However, due to the challenges associated with integrating microfluidics with MMs in both design and manufacturing, current MSs exhibit narrow frequency bands, particularly constrained at lower frequencies. Herein, a reconfigurable solid–liquid composite of liquid‐based MSs, utilizing the interbedded structure of cones, is proposed for ultra‐wideband microwave absorption. When water is used as the filling medium, the absorption rate exceeds 90% across a wide frequency range from 5.9 to 50 GHz. Upon substitution with ionic liquids, the frequency range demonstrating absorption efficiency exceeding 90% extends from 3.3 to 50 GHz. Furthermore, it is confirmed that the designed MSA demonstrates exceptional stability when subjected to oblique incidence and shows a high degree of insensitivity to polarization, highlighting its robust applicability. The low‐cost, easily manufacturable, and ultra‐wideband liquid‐based MSA holds promising potential for applications in radar countermeasures, energy harvesting, radiation protection, and other related fields.

Photocatalysis and microwave absorption performance of cobalt particles dispersed on activated carbon surface under the role of surface, optical, and magnetic properties

Ensuring the availability of clean water and solve electromagnetic interference are a fundamental action to support a better life. Here, the bifunctional material as photocatalyst and absorber microwave were prepared from activated carbon composite with Cobalt (AC-Co (0, 10, & 20)%) by stirring-assisted impregnation method as an easy and environmentally friendly procedure. The effectiveness of the material as a catalyst is observed from its surface condition as an active site, and we also consider the electrical and magnetic properties as aspects of the role in photodegradation capability. It was found that AC-Co (10) showed a methylene blue and pesticide degradation capability of >90 % for an adsorbent mass of 1.5 g within 5 days treated without artificial irradiation and stirring to imitate the environmental conditions. The microwave absorption capability by the composite shows a maximum absorption of −19.1 dB at 10.12 GHz for AC-Co (0), while the presence of Co manages to provide a higher working frequency shift but reduced absorption performance. These reported performances are supported by the appropriate distribution of Co particles scattered on the AC surface, larger μ'', and higher consistency of Δ(LO−TO) positions.

Engineering multifunctionality graphene-based nanocomposites with epoxy-silane functionalized cardanol for next-generation microwave absorber

As technology advances, the demand for effective microwave-absorbing materials (MAM) to mitigate electromagnetic wave interference is growing. Two-dimensional (2D) materials are increasingly favored across various fields for their high specific surface area, electrical conductivity, low density, and dielectric loss properties. This study presents lightweight nanocomposites composed of graphene nanoplatelets blended with epoxy resin (ER) and cardanol with silane-functionalized (SFC) as a toughening agent. The resulting nanocomposites exhibit a high surface roughness of 130 nm and an enhanced hydrophobicity, as evidenced by a high contact angle. Notably, the ER/SFC/GNP sample at 3 wt% (0.075 g) achieves a minimum reflection loss value of −18 dB at a thickness of 10 mm, indicating improved impedance matching and enhanced dielectric loss capability. The increasing damping factor ratio to approximately 0.95 further augments the reflection loss performance. The research aims to develop cost-effective, efficient, lightweight graphene-based nanocomposite absorbers.

Stable and efficient microwave absorption performances: Design from polydopamine/polyethyleneimine encapsulated FeSiAl flaky composites to frustum of a cone array

The typical microwave absorber usually exhibits the large variations in absorption behavior with absorbing thickness (>10 % for a change in absorber thickness by 10 %). How to obtain broad, strong and stable microwave absorption performances still remains a challenge. In this work, a vertical ball milling technique followed by a co-deposition method in alkaline solution is developed to prepare polydopamine (PDA)/polyethyleneimine (PEI) coated flaky FeSiAl composites, which display broad, strong and stable absorption performances at 2–14 GHz. The obtained PDA/PEI covered FeSiAl flakes exhibited minimal reflection loss (RL) values exceeding −20 dB at 2.5–8.9 mm. When the effective absorption bandwidth (EAB, 4.4–4.88 GHz) and absorption efficiency (RE, 12.11–13.24 dB·GHz/mm) change by 10 %, the corresponding change in absorption thickness can be achieved 28.57 % (2.5–3.5 mm) for EAB and 15.63 % (2.7–3.2 mm) for RE. Phase cancellation and electromagnetic loss contribute to large and stable RL peak intensity and the large loss factor over a wide frequency range lead to broad and stable EAB. Integrated with a macroscale structural design, frustum of a cone structure established by computer simulation technology is beneficial for integrating quarter-wavelength resonance, dielectric loss and magnetic loss, resulting in wide EAB of 12 GHz (covering from 2 to 14 GHz) and strong RL of −62.27 dB at 7.1 GHz.

Template-free synthesize of PANI nanostructures: Modulating structure for enhanced dielectric characteristics and superior electromagnetic wave absorption

To provide electromagnetic protection for intelligent equipment, advanced electromagnetic wave absorption (EWA) materials are highly desired. To reveal the interaction mechanism of structure and electromagnetic waves, polyaniline (PANI) with various structures, including nanosheets, clusters, and nanofibers, is synthesized via a template-free approach. The self-assembly process of PANI can be regulated by camphor sulfonic acid due to the formation and guidance of charge transfer complexes. A comprehensive analysis of structure, chemical constitution, and electromagnetic characteristics is conducted. Clusters with three-dimensional micro-nano structure exhibit superior microwave absorption, achieving a minimum reflection loss of −52.22 dB at 9.84 GHz with a 3.2 mm thickness and an absorption bandwidth of 6.12 GHz at 2.3 mm thickness. The outstanding EWA performance is attributed to the unique architecture, strong dielectric loss capabilities, and effective impedance matching. Moreover, the fabrication process is cost-effective and scalable, making it conducive to practical applicability.

In-situ chemically synthesized Fe3O4/K-geopolymer composite with microwave absorbency for additive manufacturing

In this work, we utilized an in-situ chemical synthesis method to fabricate a Fe3O4/K-geopolymer (KGP) composite to be applied in a microwave absorbent field. This material, as a type of ceramic precursor, is highly expected to be a 3D printing material to prepare microwave absorbing components with complex shapes. The investigation results demonstrate that the material possesses a large effective microwave absorbing bandwidth of 3.7 GHz with the minimum reflection loss reducing to −12.2 dB when the generated Fe3O4 percent reaches 12 wt% in the KGP composite. This microwave absorbent performance can be attributed to a synergistic effect between the eddy current loss caused by the improved electrical conductivity of magnetic nanoparticles and the interfacial polarization effect from the geopolymer matrix and magnetic medium interface. Also, we used direct ink writing technology to print two-dimensional components with desirable patterns. Thickness-dependent wave absorption evaluation results confirmed a maximum reflection loss of −25.9 dB at 15.2 Hz was obtained from the printed sample containing 9.0 wt% Fe3O4 for a layer thickness of 10 mm, indicating that wave consumption effectiveness was determined by porous microstructures, magnetic loss of Fe3O4 nanoparticles as well as suitable impedance matching. The preparation method and synthesized material pave the way for integrated manufacturing of 3D printing components with microwave absorbing performance.

All-dielectric spectral selective emitter for infrared-microwave compatible stealth

The advancement of infrared detection technology has imposed increasingly stringent requirements on the infrared radiation regulation materials. Spectral selective emitters can effectively mitigate infrared signals within the detected bands, while simultaneously leveraging undetected band for efficient radiative cooling, thereby enhancing the infrared stealth effectiveness. Herein, we design an all-dielectric selective emitter consisting of only five layers by incorporating the SiO2 reststrahlen layer with a Ge/MgF2 photonic multilayers. We quantified the infrared stealth performance of the selective emitter that the emissivity in the undetected band (5−8 μm) is 0.81 and the emissivity values in detected bands are 0.20 (3−5 μm) and 0.17 (8−13 μm), respectively. The simulation results demonstrate that the selective emitter exhibits superior radiative cooling performance and infrared stealth capabilities, as evidenced by significantly lower physical temperature and radiation intensity compared to traditional broadband low emissivity emitters. Furthermore, the all-dielectric structure ensures nearly perfect microwave transmissivity for selective emitters. When combined with microwave absorbers, they exhibit a remarkable microwave absorptivity exceeding 0.9 within the 8−18 GHz range, effectively achieving infrared-microwave compatible stealth. The all-dielectric emitter presents a novel structure for spectral selective infrared radiation control materials, featuring reduced layer complexity and the absence of metallic materials, thereby enhancing its potential for temperature resistance. This work holds significant implications for advancing selective emitters in high-temperature infrared-microwave compatible stealth applications.

Magnetic properties and microstructural of ion-implanted Gadolia doped Ceria-Barium monoferrite thin film deposited on Kapton for electromagnetic wave absorber application

Gadolia-doped Ceria-Barium Monoferrite (GDC-BaFe2O4) thin films have been deposited on Kapton sheets using the DC sputtering method as electromagnetic (EM) wave-absorbing materials. The present study has examined the structural, magnetic, and microwave absorption properties of GDC-BaFe2O4. The primary approaches used in this investigation included changing the surface form and applying EM wave-absorbing materials as surface coatings. X-ray diffraction research showed that the GDC-BaFe2O4 thin films have an orthorhombic crystal structure. The bonding investigation revealed the existence of Fe-O, Ce-O, and Ba-O-Ba functional groups at 426.87, 517.42 and 1014.84 cm−1, respectively. Vibrating-sample magnetometry confirmed that saturation magnetization decreased with increasing sputtering time and revealed the ferromagnetic behavior of the GDC-BaFe2O4 thin film. Ce, Gd, Ba, Fe, and O were evenly and similarly distributed over the Kapton surface of the GDC-BaFe2O4 thin films, according to energy-dispersive X-ray spectroscopy and scanning electron microscopy. Based on the atomic force microscopy test, the root-mean-square roughness (Rq) increased during the ion implantation procedure. With a 7.5-minute sputtering period, the microwave absorption ability reached a maximum reflection loss value of −39.6 dB (99.98 %) at 10 GHz. As a result of these findings, GDC-BaFe2O4 appears to be a promising candidate for EM wave absorption.

Investigation of the Effect of Alloying Element Equilibrium Relationship on the Electromagnetic Microwave Absorption Properties of Nano FeNi Magnetic Particles

AbstractIn order to effectively comprehend the impact of alloying element equilibrium relationship of binary nano‐magnetic particles on their electromagnetic wave absorption performance, four sets of binary nano FeNi magnetic particles with Fe:Ni alloy ratios of 2:8, 4:6, 6:4, and 8:2 were prepared with liquid‐phase reduction and the microstructure, static magnetic properties, and electromagnetic wave absorption performance of the particles were studied. The results show that the nano FeNi magnetic particles exhibit a spherical geometric structure, with a decrease in crystallinity as the Fe:Ni alloy ratio increases. The remanence and coercivity initially increase and then decrease with the increased Fe:Ni alloy ratio, with a 270 % decrease in saturation magnetization intensity as the alloy ratio changes from 2:8 to 8:2. With the increase in the Fe:Ni alloy ratio, the real and imaginary parts of the complex permittivity exhibit a decreasing trend, while the real part of the magnetic permeability decreases with increasing frequency. Aside from the 8:2 Fe:Ni alloy ratio, significant polarization relaxation losses were observed in the prepared magnetic particles, with eddy current losses was not the main mechanism of magnetic losses. The attenuation constant shows a peak at high frequencies, and the impedance matching performance increases with the increase in the Fe:Ni alloy ratio. When the Fe:Ni alloy ratio changes from 2:8 to 8:2, the minimum reflection loss decreased by 3340 %, and at a thickness of 2.1 mm and a frequency of 12 GHz, the FeNi alloy particles with a ratio of 2:8 exhibited a minimum reflection loss of −17.2 dB with an effective absorption bandwidth of 1.92 GHz.

Dimensional Self‐Assembled Magnetic Coupling via Embedding Ferromagnetic Nanoparticles in Multi‐Channel Fibers for Microwave Absorption

Abstract1D magnetic fibers with significant morphological diversity and magnetic anisotropy are highly desirable for optimizing magnetic properties and electromagnetic responsiveness. However, it remains challenging for the precise control over internal magnetic interactions within each fiber. Herein, a strategy for self‐assembled magnetic coupling is taken to achieve the controllable reconstruction of continuous multiple coupling networks within a single fiber. High‐density ultrafine cobalt nanoparticles are uniformly embedded inside a carbon framework with a 1D multi‐channel structure (Co@MCF). This structure establishes a complex magnetic response system characterized by inherent inter‐fiber interactions and refined intra‐fiber self‐assembling coupling. The distinctive distribution of magnetic flux lines demonstrates enhanced magnetic sensitivity. This results in a minimum reflection loss of −57.65 dB and a broadband absorption frequency range of 7.28 GHz at 1.9 mm, effectively covers the entire Ku band and a substantial portion of the X band. The multi‐channel structure enhances the understanding of the relationship between microstructure and performance in magnetic fibers. Additionally, it positions Co@MCF as a highly competitive candidate for microwave absorption applications.

Advances in Carbon Microsphere-Based Nanomaterials for Efficient Electromagnetic Wave Absorption.

Carbon microspheres have indeed shown great promise as effective materials for absorbing electromagnetic waves, particularly in microwave applications. Their unique properties, such as high surface area, porosity, and electronic characteristics, make them ideal candidates for addressing the growing concerns around electromagnetic pollution from electronic devices. By leveraging the properties of these materials, we can work toward creating more efficient and sustainable electromagnetic wave absorption technologies. Recent efforts have focused on synthesizing and investigating carbon microsphere-based electromagnetic wave-absorbing nanomaterials with the ambition of achieving the desired attributes of being thin, light, wide, and robust. This Review first delves into the detailed mechanism of electromagnetic wave absorption, followed by an elucidation of the preparation methods for carbon microsphere-based nanomaterials. Furthermore, it systematically outlines the common methods and strategies employed to improve the microwave absorption capabilities of carbon microspheres, including chemical vapor deposition, emulsion polymerization, hydrothermal methods, and template methods. Lastly, it outlines the challenges encountered by carbon microsphere-based electromagnetic wave absorption nanomaterials and outlines their prospects, mainly morphology change, component hybridization, and elemental doping. This Review aims to provide valuable insights into the creation of carbon microsphere nanomaterials with excellent electromagnetic wave absorption properties.

Zn-Al Ferrite/Polypyrrole Nanocomposites: Structure and Dielectric and Magnetic Properties for Microwave Applications.

In this study, Zn-Al ferrite/polypyrrole (PPy) nanocomposites were synthesized and thoroughly characterized to explore their potential for microwave applications. X-ray diffraction analysis confirmed the presence of ZnO, AlFeO3, and Fe2O3 phases, with the crystal size decreasing from 31 nm to 19.6 nm as aluminum content increased. High-resolution transmission electron microscopy (HR-TEM) revealed a distinctive core-shell morphology, where the polypyrrole encapsulates the ZnAlxFe2-xO4 particles. Magnetic measurements showed that decreasing aluminum concentration led to a reduction in both saturation magnetization (Ms) from 75 emu/g to 36 emu/g and remanent magnetization (Mr) from 2.26 emu/g to 2.00 emu/g. Dielectric analysis indicated that both the real (ε') and imaginary (ε″) components of dielectric permittivity decreased with increasing frequency, particularly between 10 and 14 GHz. Furthermore, electrical modulus analysis highlighted the significant impact of aluminum doping on relaxation time (τIP), indicating the presence of interface polarization. Impedance spectroscopy results underscored the dominance of interface polarization at lower frequencies and the presence of strong conduction paths at higher frequencies. These combined magnetic and dielectric loss mechanisms suggest that the Zn-Al ferrite/polypyrrole nanocomposite is a promising candidate for advanced microwave absorption applications.

Enhancement of microwave absorption ability of Nd0.67Sr0.33Mn1-xNix/2Tix/2O3 (x = 0, 0.03, and 0.06)

Enhancement of microwave absorption ability of Nd0.67Sr0.33Mn1-xNix/2Tix/2O3 (x = 0, 0.03, and 0.06)

Customized Pore Creation Strategies for Hyperelastic, Robust, Insulating Multifunctional MXene Aerogels for Microwave Absorption.

The construction of heterogeneous microstructure and the selection of multicomponents have turned into a research hotspot in developing ultralight, multifunctional, high-efficiency electromagnetic wave absorbing (EMA) materials. Although aerogels are promising materials to fulfill the above requirements, the increase in functional fillers inevitably leads to the deterioration of intrinsic properties. Tuning the electromagnetic properties from the structural design point of view remains a difficult challenge. Herein, we design customized pore creation strategies via introducing sacrificial templates to optimize the conductive path and construct the discontinuous dielectric medium, increasing dielectric loss and achieving efficient microwave absorption properties. A 3D porous composite (MEM) was crafted, which encapsulated an EVA/FeCoNi (EVA/MNPs) framework with Ti3C2Tx MXene coating by employing a direct heated cross-linking and immersion method. Controllable adjustment of the conductive network inside the porous structure and regulation of the dielectric character are achieved by porosity variation. Eventually, the MEM-5 with a porosity of 66.67% realizes RLmin of -39.2 dB (2.2 mm) and can cover the entire X band. Moreover, through off-axis electronic holography and the calculation of conduction loss and polarization loss, the dielectric property is deeply investigated, and the inner mechanism of optimization is pointed out. Thanks to the inherent characteristic of EVA and the porous structure, MEM-5 showed excellent thermal insulating and superior compressibility, which can maintain 60 °C on a 90-100 °C continuous heating stage and reached a maximum compressive strength of 60.12 kPa at 50% strain. Conceivably, this work provides a facile method for the fabrication of highly efficient microwave absorbers applied under complex conditions.

A Perspective of Tailoring Dielectric Genes for 2D Materials Toward Advanced Electromagnetic Functions

Abstract2D materials and their composites with electromagnetic properties are becoming increasingly popular. Obtaining insight into the nature of electromagnetic (EM) response manipulation is imperative to guide scientific research and technological exploitation at such a critical time. From this perspective, the dielectric genes of 2D material hybrids have been highlighted based on the recent literature. This endows an unlimited possibility of manipulating the EM response, even at elevated temperatures. The definitions and criteria of dielectric genes toward 2D material hybrids and composites are systematically clarified and summarized. The dielectric gene categories are successfully discriminated, including the conduction networks, intrinsic defects, impurity defects, and interfaces in the composite, and their temperature evolution is revealed in detail. More importantly, tuning strategies for microwave absorption, electromagnetic shielding effectiveness, and expanded electromagnetic functions are thoroughly discussed. Finally, significant predictions are provided for multispectral electromagnetic functions, and future applications of multifunctional exploration are anticipated. Dielectric genes will open an unexpected horizon for advanced functional materials in the coming 5G/6G age, providing a significant boost to promoting environmental electromagnetic protection, electromagnetic devices, and next‐generation smart devices.

Enhanced microwave absorption in GaFeO3 coated CoFe2O4 nano-hollowsphere

As a multiferroic material with substantial magnetoelectric coupling, gallium ferrite (GaFeO3, GFO) has been intensively studied in recent years. Cobalt ferrite (CoFe2O4, CFO) nano-hollowsphere (NHS), on the other hand, is found to be an efficient material for electromagnetic (EM) wave absorption. In this work, a composite consisting of magnetostrictive CFO NHS coated with GFO nanoparticles [(1−x)CoFe2O4 – xGaFeO3, for x = 0.0, 0.9, 0.7, 0.5, 0.3, and 1.0] is prepared as an effective strategy to develop highly efficient microwave material. The EM wave absorption properties of the samples are thoroughly investigated across a widely used frequency range of 1–20 GHz. Remarkable performance of the x = 0.7 composite is evident by its effective bandwidth of approximately 3 GHz and a minimum reflection loss of approximately −63.26 dB. Moreover, the excellent impedance matching, with |Zin/Z0| ≅ 1.00, observed in the aforementioned composite, satisfies well with the required characteristics for a superior microwave absorber. Therefore, a core–shell nanostructure consisting of CFO NHS as core and GFO with optimized shell thickness can be used successfully in microwave devices.