Showing papers on "Dielectric loss published in 2015"

Metal organic framework-derived Fe/C nanocubes toward efficient microwave absorption

Abstract: Composites of magnetic metal nanoparticles and carbon materials are highly desirable for high-performance microwave absorbers due to their compatible dielectric loss and magnetic loss abilities. In this article, novel nanocomposites, Fe/C nanocubes, have been successfully prepared through an in situ route from a metal–organic framework, Prussian blue, by controlled high-temperature pyrolysis. The resultant nanocubes are actually composed of a cubic framework of amorphous carbon and uniformly dispersed core–shell Fe@graphitic carbon nanoparticles. Within the studied pyrolysis temperature range (600–700 °C), the porous structure, iron content, magnetic properties, and graphitization degree of the Fe/C nanocubes can be well modulated. Particularly, the improved carbon graphitization degree, both in amorphous frameworks and graphitic shells, results in enhanced complex permittivity and dielectric loss properties. The homogeneous chemical composition and microstructure stimulate the formation of multiple dielectric resonances by regularizing various polarizations. The synergistic effect of dielectric loss, magnetic loss, matched impedance, and dielectric resonances accounts for the improved microwave absorption properties of the Fe/C nanocubes. The absorption bands of the optimum one obtained at 650 °C are superior to most composites ever reported. By considering the good chemical homogeneity and microwave absorption, we believe that the as-fabricated Fe/C nanocubes will be promising candidates as highly effective microwave absorbers.

A novel rod-like MnO2@Fe loading on graphene giving excellent electromagnetic absorption properties

Abstract: Impedance matching and the attenuation constant, α, are two key parameters in determining electromagnetic absorption properties Although materials with single magnetic or dielectric loss properties have a high α value, they nonetheless suffer from poor impedance matching The design of magnetic and dielectric composites might possibly be an effective method of solving this problem, but unfortunately the introduction of magnetic material may give a poor value of α In order to obtain absorptive materials with high impedance matching and a high value of α, we have designed a novel ternary composite of MnO2@Fe–graphene A 30 nm wide rod-like strip of MnO2 was first obtained by a simple liquid process Liquid decomposition of Fe(CO)5 was then carried out to deposit iron on the surface of the rod-like structure, and the MnO2@Fe was finally loaded on graphene by a liquid deposition technique The resulting ternary composite exhibited attractive electromagnetic absorption properties, in which the optimal reflection loss of up to −175 dB obtained with a thin coating thickness of 15 mm was able to satisfy the requirements of lightness of weight and a high degree of absorption The effective bandwidth frequency of MnO2@Fe–GNS is broader than that of pure MnO2 or MnO2@Fe, possibly due to its moderate impedance matching and attenuation ability The possible attenuation mechanism will also be discussed

3D Fe3O4 nanocrystals decorating carbon nanotubes to tune electromagnetic properties and enhance microwave absorption capacity

Abstract: We fabricated a novel dielectric–magnetic nanostructure by hybridizing 3D Fe3O4 nanocrystals and multi-walled carbon nanotubes through a simple co-precipitation route. The 3D Fe3O4-MWCNTs composites demonstrate enhanced microwave absorption with tunable strong-absorption wavebands in the frequency range of 2–18 GHz. Double-band microwave absorption appears in the investigated frequency range and at various thicknesses. This depends on the loading concentration of 3D Fe3O4-MWCNTs. Minimum reflection loss values at 20 wt% loading of −23.0 dB and −52.8 dB are observed at 4.1 GHz and 12.8 GHz, respectively, which are superior to those of pure MWCNTs as well as other hybrids of Fe3O4. The improved absorption capacity arises from the synergy of dielectric loss and magnetic loss, as well as the enhancement of multiple interfaces among 3D Fe3O4 nanocrystals. All of these factors increase the flexibility of tuning microwave absorption. These results provide a new strategy to tune electromagnetic properties and enhance the capacity of high-efficient microwave absorbers.

Improving Dielectric Properties of PVDF Composites by Employing Surface Modified Strong Polarized BaTiO₃ Particles Derived by Molten Salt Method.

Abstract: BaTiO3/polyvinylidene fluoride (BT/PVDF) is the extensive reported composite material for application in modern electric devices. However, there still exists some obstacles prohibiting the further improvement of dielectric performance, such as poor interfacial compatibility and low dielectric constant. Therefore, in depth study of the size dependent polarization and surface modification of BT particle is of technological importance in developing high performance BT/PVDF composites. Here, a facile molten-salt synthetic method has been applied to prepare different grain sized BT particles through tailoring the calcination temperature. The size dependent spontaneous polarizationof BT particle was thoroughly investigated by theoretical calculation based on powder X-ray diffraction Rietveld refinement data. The results revealed that 600 nm sized BT particles possess the strong polarization, ascribing to the ferroelectric size effect. Furthermore, the surface of optimal BT particles has been modified by water-soluble polyvinylprrolidone (PVP) agent, and the coated particles exhibited fine core-shell structure and homogeneous dispersion in the PVDF matrix. The dielectric constant of the resulted composites increased significantly, especially, the prepared composite with 40 vol % BT loading exhibited the largest dielectric constant (65, 25 °C, 1 kHz) compared with the literature values of BT/PVDF at the same concentration of filler. Moreover, the energy storage density of the composites with tailored structure was largely enhanced at the low electric field, showing promising application as dielectric material in energy storage device. Our work suggested that introduction of strong polarized ferroelectric particles with optimal size and construction of core-shell structured coated fillers by PVP in the PVDF matrix are efficacious in improving dielectric performance of composites. The demonstrated approach can also be applied to the design and preparation of other polymers-based nanocomposites filled with ferroelectric particles to achieve desirable dielectric properties.

Surface participation and dielectric loss in superconducting qubits

Abstract: We study the energy relaxation times (T1) of superconducting transmon qubits in 3D cavities as a function of dielectric participation ratios of material surfaces. This surface participation ratio, representing the fraction of electric field energy stored in a dissipative surface layer, is computed by a two-step finite-element simulation and experimentally varied by qubit geometry. With a clean electromagnetic environment and suppressed non-equilibrium quasiparticle density, we find an approximately proportional relation between the transmon relaxation rates and surface participation ratios. These results suggest dielectric dissipation arising from material interfaces is the major limiting factor for the T1 of transmons in 3D circuit quantum electrodynamics architecture. Our analysis also supports the notion of spatial discreteness of surface dielectric dissipation.

Colossal permittivity in ceramics of TiO2 Co-doped with niobium and trivalent cation

Abstract: The appearance of colossal permittivity (CP) materials broadens the choice of materials for energy-storage applications. Here we report colossal permittivity in ceramics of TiO2 co-doped with niobium and trivalent cation {i.e., (A0.5Nb0.5)xTi1−xO2, A = Bi, Pr, Dy, Sm, Gd, Yb, Ga, Al or Sc}, in particular in the (Bi0.5Nb0.5)xTi1−xO2 ceramic system that was selected as a candidate material. A very large dielectric constant (er ∼ 4.2 × 104) and a low dielectric loss (tan δ ∼ 8.3%) were observed for (Bi0.5Nb0.5)xTi1−xO2 ceramics when measured at 1 kHz. Moreover, the addition of Bi and Nb can enhance the temperature stability (between −125–200 °C) and frequency stability (between 102 to 106 Hz) of er and tan δ. The electron-pinned defect-dipoles are considered to be responsible for both their high er and low tan δ, which is consistent with changes of valence states determined by X-ray photoelectron spectroscopy. We believe that the TiO2 ceramics as a CP material constitute one of the most promising candidates for high-energy-density storage applications.

Colossal Dielectric Behavior of Ga+Nb Co-Doped Rutile TiO2

Abstract: Stimulated by the excellent colossal permittivity (CP) behavior achieved in In+Nb co-doped rutile TiO2, in this work we investigate the CP behavior of Ga and Nb co-doped rutile TiO2, i.e., (Ga(0.5)Nb(0.5))(x)Ti(1-x)O2, where Ga(3+) is from the same group as In(3+) but with a much smaller ionic radius. Colossal permittivity of up to 10(4)-10(5) with an acceptably low dielectric loss (tan δ = 0.05-0.1) over broad frequency/temperature ranges is obtained at x = 0.5% after systematic synthesis optimizations. Systematic structural, defect, and dielectric characterizations suggest that multiple polarization mechanisms exist in this system: defect dipoles at low temperature (∼10-40 K), polaronlike electron hopping/transport at higher temperatures, and a surface barrier layer capacitor effect. Together these mechanisms contribute to the overall dielectric properties, especially apparent observed CP. We believe that this work provides comprehensive guidance for the design of new CP materials.

Dielectric relaxation, resonance and scaling behaviors in Sr3Co2Fe24O41 hexaferrite.

Abstract: The dielectric properties of Z-type hexaferrite Sr3Co2Fe24O41 (SCFO) have been investigated as a function of temperature from 153 to 503 K between 1 and 2 GHz. The dielectric responses of SCFO are found to be frequency dependent and thermally activated. The relaxation-type dielectric behavior is observed to be dominating in the low frequency region and resonance-type dielectric behavior is found to be dominating above 108 Hz. This frequency dependence of dielectric behavior is explained by the damped harmonic oscillator model with temperature dependent coefficients. The imaginary part of impedance (Z″) and modulus (M″) spectra show that there is a distribution of relaxation times. The scaling behaviors of Z″ and M″ spectra further suggest that the distribution of relaxation times is temperature independent at low frequencies. The dielectric loss spectra at different temperatures have not shown a scaling behavior above 108 Hz. A comparison between the Z″ and the M″ spectra indicates that the short-range charges motion dominates at low temperatures and the long-range charges motion dominates at high temperatures. The above results indicate that the dielectric dispersion mechanism in SCFO is temperature independent at low frequencies and temperature dependent at high frequencies due to the domination of resonance behavior.

Colossal Dielectric Permittivity in (Nb+Al) Codoped Rutile TiO2 Ceramics: Compositional Gradient and Local Structure

Abstract: (Nb+Al) codoped rutile TiO2 ceramics with nominal composition Ti4+0.995Nb5+0.005yAl3+0.005zO2, z = (4–5y)/3 and y = 0.4, 0.5, 0.6, 0.7, and Ti4+0.90Nb5+0.05Al3+0.05O2 have been synthesized. The resultant samples in ceramic pellet form exhibit a colossal dielectric permittivity (>∼104) with an acceptably low dielectric loss (∼10–1) after optimization of the processing conditions. It is found that a conventional surface barrier layer capacitor (SBLC) effect, while it contributes significantly to the observed colossal permittivity, is not the dominant effect. Rather, there exists a subtle chemical compositional gradient inward from the pellet surface, involving the concentration of Ti3+ cations gradually increasing from zero at the surface without the introduction of any charge compensating oxygen vacancies. Instead, well-defined Gr ± 1/3[011]* satellite reflections with the modulation wave-vector q = 1/3[011]r* and sharp diffuse streaking running along the Gr ± e[011]* direction from electron diffraction su...

Surface participation and dielectric loss in superconducting qubits

Abstract: We study the energy relaxation times ($T_1$) of superconducting transmon qubits in 3D cavities as a function of dielectric participation ratios of material surfaces. This surface participation ratio, representing the fraction of electric field energy stored in a dissipative surface layer, is computed by a two-step finite-element simulation and experimentally varied by qubit geometry. With a clean electromagnetic environment and suppressed non-equilibrium quasiparticle density, we find an approximately proportional relation between the transmon relaxation rates and surface participation ratios. These results suggest dielectric dissipation arising from material interfaces is the major limiting factor for the $T_1$ of transmons in 3D cQED architecture. Our analysis also supports the notion of spatial discreteness of surface dielectric dissipation.

High temperature dielectric ceramics: a review of temperature-stable high-permittivity perovskites

Abstract: Recent developments are reviewed in the search for dielectric ceramics which can operate at temperatures >200 °C, well above the limit of existing high volumetric efficiency capacitor materials. Compositional systems based on lead-free relaxor dielectrics with mixed cation site occupancy on the perovskite lattice are summarised, and properties compared. As a consequence of increased dielectric peak broadening and shifts to peak temperatures, properties can be engineered such that a plateau in relative permittivity–temperature response (er–T) is obtained, giving a ±15 %, or better, consistency in er over a wide temperature range. Materials with extended upper temperature limits of 300, 400 and indeed 500 °C are grouped in this article according to the parent component of the solid solution, for example BaTiO3 and Na0.5Bi0.5TiO3. Challenges are highlighted in achieving a lower working temperature of −55 °C, whilst also extending the upper temperature limit of stable er to ≥300 °C, and achieving high-permittivity and low values of dielectric loss tangent, tan δ. Summary tables and diagrams are used to help compare values of er, tan δ, and temperature ranges of stability for different materials.

Facile preparation and enhanced microwave absorption properties of core–shell composite spheres composited of Ni cores and TiO2 shells

Abstract: Core–shell microspheres with Ni cores and two phases of TiO2 (anatase, rutile) shells have been successfully synthesized. The crystal structure, morphology and microwave absorption properties of the as-prepared composites were analyzed by X-ray diffraction, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and vector network analysis. The core–shell rutile TiO2-coated Ni exhibits better antioxidation ability than that of pure Ni due to the presence of the rutile TiO2 shell, which is confirmed by the thermal gravimetric analysis (TGA). In comparison with bare Ni, these two composites show better microwave absorption properties. The minimum reflection loss (RL) is −38.0 dB at 11.1 GHz with a thickness of only 1.8 mm for the Ni@TiO2 (rutile) composite. The enhanced absorption capability arises from the efficient complementarities between the magnetic loss and dielectric loss, multiple interfacial polarization, high thermal conductivity of rutile TiO2 and microwave attenuation constant. These results show that the thin high-efficiency rutile TiO2-coated Ni composite is a great potential microwave absorbing material for practical applications.

Strawberry-like Core–Shell Ag@Polydopamine@BaTiO3 Hybrid Nanoparticles for High-k Polymer Nanocomposites with High Energy Density and Low Dielectric Loss

Abstract: Flexible nanocomposites comprising of polymer and high-dielectric-constant (high-k) ceramic nanoparticles are becoming increasingly attractive for dielectric and energy storage applications in modern electronic and electric industry. However, a huge challenge still remains. Namely, the increase of dielectric constant usually at the cost of significant decrease of breakdown strength of the nanocomposites because of the electric field distortion and concentration induced by the high-k filler. To address this long-standing problem, by using nano-Ag decorated core–shell polydopamine (PDA) coated BaTiO3 (BT) hybrid nanoparticles, a new strategy is developed to prepare high-k polymer nanocomposites with high breakdown strength. The strawberry-like BT-PDA-Ag based ferroelectric polymer [i.e., poly(vinylideneflyoride-co-hexafluroro propylene), P(VDF-HFP)] nanocomposites exhibit greatly enhanced energy density and significantly suppressed dielectric loss as well as leakage current density in comparison with the nanocomposites with the core–shell structured BT-PDA. Coulomb-blockade effect of super-small nano-Ag is used to explain the observed performance enhancement of the nanocomposites. The simplicity and scalability of the described approach provide a promising route to polymer nanocomposites for dielectric and energy storage applications.

Nd doping of bismuth ferrite to tune electromagnetic properties and increase microwave absorption by magnetic–dielectric synergy

Abstract: Simultaneously achieving tunable electromagnetic parameters and strong absorption capacity in a single material is still a great challenge. Here, we present Nd doped BiFeO3 with electromagnetic matching, which exhibits tunable electromagnetic properties and high-performance microwave absorption. The experimental and calculated results demonstrate that Nd doping generates the ordered domain structure and changes the coupling states of electrons, which induce difficult polarization rotation and strong natural ferromagnetic resonance, leading to the decrease of dielectric loss and the increase of magnetic loss with increasing Nd concentration. The electromagnetic parameters are tuned from mismatching to matching, and the microwave absorption is improved. Bi0.8Nd0.2FeO3 exhibits a remarkable reflection loss (RL) of −42 dB and bandwidth (RL ≤ −10 dB) which covers nearly three quarters of the X-band at a thickness from 1.9 to 2.1 mm. This work highlights the applications of BFO as a high-performance microwave absorber and opens up a promising feasible route to the development of microwave absorbers in imaging, healthcare, information safety and military fields.

Cobalt/polypyrrole nanocomposites with controllable electromagnetic properties

Abstract: In this work, cobalt/polypyrrole (Co/PPy) nanocomposites were prepared via an in situ oxidation polymerization of pyrrole in an aqueous dispersion of Co nanoparticles (NPs). The Co/PPy nanocomposites showed good electromagnetic properties because of the coexistence of magnetic loss and dielectric loss to electromagnetic waves. The electromagnetic wave absorbing bandwidth (reflection loss < −10 dB) for Co/PPy (30 wt% in a paraffin matrix) was located at 11.7–16.47 GHz with a thickness of 2 mm, and with a maximum reflection loss (around −33 dB) at 13.6 GHz. More interestingly, the electromagnetic wave absorbing properties of the nanocomposites can be easily controlled by tuning the ratio of the two components in the composites. This improved electromagnetic wave absorption may be attributed to the excellent electromagnetic match at the corresponding resonance peaks for dielectric and magnetic loss. These magnetic nanoparticles/conducting polymer nanocomposites are great potential candidates for use as electromagnetic wave absorbents due to their excellent properties such as wide absorbing frequency, strong absorption, good compatibility, low density and controllable absorbing properties.

Enhanced thermal conductivity and dielectric properties of Al/β-SiCw/PVDF composites

Abstract: Polymeric composites with high thermal conductivity, high dielectric permittivity but low dissipation factor have wide important applications in electronic and electrical industry. In this study, three phases composites consisting of poly(vinylidene fluoride) (PVDF), Al nanoparticles and β -silicon carbide whiskers ( β -SiC w ) were prepared. The thermal conductivity, morphological and dielectric properties of the composites were investigated. The results indicate that the addition of 12 vol% β -SiC w not only improves the thermal conductivity of Al/PVDF from 1.57 to 2.1 W/m K, but also remarkably increases the dielectric constant from 46 to 330 at 100 Hz, whereas the dielectric loss of the composites still remain at relatively low levels similar to that of Al/PVDF at a wider frequency range from 10 −1 Hz to 10 7 Hz. With further increasing the β -SiC w loading to 20 vol%, the thermal conductivity and dielectric constant of the composites continue to increase, whereas both the dielectric loss and conductivity also rise rapidly.

Temperature dependent dielectric and conductivity studies of polyvinyl alcohol-ZnO nanocomposite films by impedance spectroscopy

Abstract: Dielectric and conductivity behaviors of nano ZnO doped polyvinyl alcohol (PVA) composites for various concentrations of dopant were investigated using impedance spectroscopy for a wide range of temperatures (303 K–423 K) and frequencies (5 Hz–30 MHZ). The dielectric properties of host polymer matrix have been improved by the addition of nano ZnO and are found to be highly temperature dependent. Anomalous dielectric behavior was observed in the frequency range of 2.5 MHz–5 MHz. Increase in dielectric permittivity and dielectric loss was observed with respect to temperature. The Cole-Cole plot could be modeled by low resistance regions in a high resistance matrix and the lowest resistance was observed for the 10 mol. % films. The imaginary part of the electric modulus showed asymmetric peaks with the relaxation following Debye nature below and non-Debye nature above the peaks. The ac conductivity is found to obey Jonscher's power law, whereas the variation of dc conductivity with temperature was found to f...

A facile hydrothermal synthesis of MnO2 nanorod–reduced graphene oxide nanocomposites possessing excellent microwave absorption properties

Abstract: Pure MnO2 nanorods and MnO2 nanorod/reduced graphene oxide (RGO) nanocomposites are prepared for microwave absorption by using a simple one-step hydrothermal method without using any toxic solvents. The results demonstrate that the MnO2 phases possess a high crystallization degree in both the pure nanorods and the nanocomposites but the nanocomposites exhibit two hybrid Mn phases, distinct from MnO2 in the pure nanorods. The electromagnetic characteristics and electromagnetic wave (EMW) absorption properties of the materials are investigated. The thickness dependent reflection loss shows that the peak frequency and effective absorption bandwidth all decrease with the increasing material thickness. Compared with the pure MnO2 nanorods, the introduction of RGO enhances the microwave absorbing intensity and effective absorption bandwidth. The maximum reflection loss value of the nanocomposites reaches −37 dB at 16.8 GHz with a thickness of 2.0 mm and the wide bandwidth corresponding to the reflection loss below −10 dB starts from 13 GHz until a value of −22 dB at 18 GHz. The enhanced microwave absorbing properties can be ascribed to the improved permittivity, dielectric loss and especially the synergistic effects between MnO2 nanorods and RGO nanosheets at their interfaces in the unique nanostructures of the MnO2/RGO nanocomposites.

Huge low-frequency dielectric response of (Nb,In)-doped TiO2 ceramics

Abstract: The (Nb,In)-doped TiO2 ceramics have drawn considerable attention as a type of promising giant-permittivity dielectric materials in recent years. However, a significant controversy concerning the giant dielectric mechanism currently exists, and clarifying it is vitally important from both scientific and technological viewpoints. This letter reports the results of a systematical comparison study, where two kinds of (Nb,In)-doped TiO2 ceramics with a substantial difference in dielectric loss are used. Dielectric properties and complex impedance are investigated over a broad frequency band of 3 mHz–110 MHz. A huge low-frequency dielectric response in addition to the giant dielectric relaxation appearing above 1 MHz is observed for both kinds of (Nb,In)-doped TiO2 ceramics in dielectric dispersion. The huge dielectric response observed in the low frequency range can be ascribed to a non-ohmic electrode-contact, and the dielectric relaxation appearing above 1 MHz can be attributed to an internal barrier layer ...

Composition dependence of colossal permittivity in (Sm0.5Ta0.5)xTi1−xO2 ceramics

Abstract: In this study, colossal permittivity (CP) (104–105) is attained in the (Sm0.5Ta0.5)xTi1−xO2 ceramics, and their dielectric loss can be further decreased by doping oxides and optimizing the sintering temperatures. The effects of Sm and Ta as well as the oxides on their microstructure, dielectric properties, and stability were studied in detail. The secondary phases were induced by doping excessive Sm and Ta, and then both backscattering and EDS confirmed that excessive Sm and Ta result in the generation of secondary phases. The relationships between secondary phases and dielectric properties were established. The formation of secondary phases decreases their dielectric constant, whereas their dielectric loss can be slightly decreased through the optimization of Sm and Ta content. In addition, all the ceramics possess an improved frequency (102–106 Hz) and temperature (−150–200 °C) stability of dielectric properties. Moreover, the addition of oxides containing trivalent (Bi3+) or pentavalent (Sb5+ and Nb5+) elements can further reduce their dielectric loss. Through the results of XPS, the formation of defect-dipole clusters, e.g., and Ta5+Ti3+ATi (A = Ti3+/Sm3+/Ti4+), induced by Sm and Ta should be mainly responsible for enhanced dielectric properties.

Dielectrical Properties of CeO2 Nanoparticles at Different Temperatures.

Abstract: A template-free precipitation method was used as a simple and low cost method for preparation of CeO2 nanoparticles The structure and morphology of the prepared nanoparticle samples were studied in detail using X-ray diffraction, Raman spectroscopy and Scanning Electron Microscopy (SEM) measurements The whole powder pattern modelling (WPPM) method was applied on XRD data to accurately measure the crystalline domain size and their size distribution The average crystalline domain diameter was found to be 52 nm, with a very narrow size distribution UV-visible absorbance spectrum was used to calculate the optical energy band gap of the prepared CeO2 nanoparticles The FT-IR spectrum of prepared CeO2 nanoparticles showed absorption bands at 400 cm-1 to 450 cm-1 regime, which correspond to CeO2 stretching vibration The dielectric constant (er) and dielectric loss (tan δ) values of sintered CeO2 compact consolidated from prepared nanoparticles were measured at different temperatures in the range from 298 K (room temperature) to 623 K, and at different frequencies from 1 kHz to 1 MHz

In situ synthesis of novel urchin-like ZnS/Ni3S2@Ni composite with a core–shell structure for efficient electromagnetic absorption

Abstract: A novel urchin-like ZnS/Ni3S2@Ni composite with a core–shell structure was successfully synthesized by a facile two-stage method. The structure and morphology were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectrometry. The influence of reaction temperature on the structure and morphology of the ZnS/Ni3S2@Ni products was investigated by the aid of XRD and SEM techniques. A plausible formation mechanism for the core–shell urchin-like architectures was proposed based on temperature dependent experiments. Electromagnetic absorption measurements show that the urchin-like ZnS/Ni3S2@Ni composite possesses outstanding electromagnetic absorption properties compared with other ZnS/Ni3S2@Ni composites. The optimal reflection loss of −27.6 dB can be observed at 5.2 GHz and the effective absorption (below −10 dB, 90% electromagnetic absorption) bandwidth is 2.5 GHz (12.2–14.7 GHz) with a thickness of only 1.0 mm. The location of the minimum reflection loss can be tuned between 4.6 GHz and 18.0 GHz for the absorber by tuning the thickness between 0.8–2.5 mm. The enhanced electromagnetic absorption properties were attributed to a synergistic effect between dielectric loss and magnetic loss, multiple interfacial polarization resulting from the heterogeneous structure of the core–shell ternary ZnS/Ni3S2@Ni composite, good impedance matching and a unique urchin-like structure.