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Ti3SiC2 particles encapsulated by Ni0.5Zn0.5Fe2O4 shell were in-situ synthesized via a facile sol-gel method. Effects of Ni0.5Zn0.5Fe2O4 shell on electromagnetic properties of Ti3SiC2 were investigated in 2–18 GHz. Moderated complex permittivity and desirable higher complex permeability presented for the Ni0.5Zn0.5Fe2O4/Ti3SiC2 composite, resulting in strong microwave attenuation ability and good impedance matching property. The measured effective absorbing bandwidth (RL

The effects of Co2O3 addition on the electromagnetic properties of NiCuZn ferrite were investigated, by considering the variation of complex permeability, complex permittivity and quasi-microwave absorption property in the 1–1000 MHz frequency range. Results show that the introduction of Co3+ ions in NiCuZn ferrite leads to the marked shifting of magnetic resonance towards high-frequency and a slight increase of the permittivity. These Co-related effects enhance the maximum reflection loss in NiCuZn ferrite to reach −55.1 dB with its absorption bandwidth being tunable in the frequency range 480–1000 MHz, which provides a potential absorber for the anti-electromagnetic interference applications in electronic industry.

MXene, especially Ti3C2Tx, is attracting extensive attention as an absorbing material owing to its strong dielectric loss and tunable structure. Nevertheless, extremely high conductivity and non-magnetic loss mechanism limit the absorbing intensity and effective absorption bandwidth (EAB). Herein, the magnetic ZnFe2O4 nanoparticles decorated Ti3C2Tx MXene composite is designed and synthesized by using a facile in-situ solvothermal method. The novel ZnFe2O4@Ti3C2Tx-2 (1:2) composite shows an optimal reflection loss of −60.94 dB and a wide EAB of 6.08 GHz at a matching thickness of only 1.75 mm. The mechanism analysis reveals that the synergetic electromagnetic loss effect, interfacial polarization, dipole polarization, and laminated structure contribute to improving the microwave absorption (MA) performance. Furthermore, to confirm the use capability of the ZnFe2O4@Ti3C2Tx sample coatings in practical applications, the radar cross-section (RCS) reduction performance has been proved through using computer simulation technology (CST). With the detection theta of 0°, the ZnFe2O4@Ti3C2Tx-2 sample coating possesses the largest RCS reduction value of 22.83 dB. This work lays the foundation for the rational design of high-performance absorbing materials.

Artificial multiferroics magnetoelectric (ME) polymer composite films exhibiting collective ferroelectric and magnetic orderings are gaining attractive for the use of flexible ME devices. Herein an anisotropic polymer-based ME composites films is developed, composed of magnetically oriented polycrystalline iron fiber (Fef) and poly(vinylidene fluoride-co-trifluoroethylene) P(VDF–TrFE). The structure, ferroelectric, piezoelectric, magnetic, and ME properties was systematically investigated. Both Fef fillers content and magnetic field direction determined the ME voltage coefficient, magnetical polarization and dielectric response in anisotropic P(VDF-TrFE)–Fef composites. Specifically, the composite with 16% filler loading delivers a peak ME value of 44.5 mV·cm−1·Oe−1 with magnetic field exerted along the fiber axial alignment direction. Such extracted results may encourage a way to optimize flexible composite in anisotropic contactless sensing and detecting applications.

Particulate magnetoelectric (ME) ceramics constituted by (1-x)(80Bi0.5Na0.5TiO3-20Bi0.5K0.5TiO3)-xCoFe2O4 [(1-x)BNKT-xCFO] (x = 0, 0.1, 0.2, 0.3, 0.4 and 1.0) were synthesized by an powder-in-sol precursor hybrid processing method and their structure, magnetic, ferroelectric, magnetodielectric (MD) and ME properties have been investigated. Results showed that the ceramics consisted of only two chemically separated phases and had homogeneous microstructure. The introduction of CFO into BNKT matrix led to the weakening of ferroelectric and dielectric properties whereas the strengthening magnetic and MD properties. The observation of the MD effect revealed the evidence of the strain-induced ME coupling and the MD value is well scaled with M2. A maximum value of ME output of 25.07 mV/cm·Oe was achieved for the 0.7BNKT-0.3CFO composite. The improved ME response together with the linear MD effect makes the ceramics promise for use in magnetic field controllable devices or magneto-electric transducers.

The magnetic insulator Fe 3 O 4 -modified flaky Fe 85 Si 9.5 Al 5.5 (FeSiAl) powders with significantly enhanced electromagnetic wave absorption properties in the frequency range of 2–8 GHz were prepared by chemical co-precipitation. X-ray diffraction (XRD) and scanning electron microscopy (SEM) have confirmed the formation of nanoparticles Fe 3 O 4 precipitated on the flake-shaped FeSiAl. The electromagnetic measurements of the modified flakes presents a nearly invariable complex permeability and decreased complex permittivity in the 2–8 GHz, as well as improved impedance matching performance. More importantly, an excellent microwave absorbing performance with the bandwidth (RL

The single-phase Bi 1- x Nd x FeO 3 ( x =0, 0.05, 0.10, 0.15, 0.20) were synthesized by the sol-gel method. Their crystal structure and microwave electromagnetic property in the frequency range of 2–18 GHz were investigated. The XRD patterns and Raman spectra showed that structural transition from rhombohedral ( x =0, 0.05, 0.1) to triclinic ( x =0.15) and tetragonal structure ( x =0.20) appeared in the Bi 1- x Nd x FeO 3 . Electromagnetic measurement suggested that both microwave permeability μ′ and magnetic loss tanδ m increased remarkably over 2–18 GHz by doping Nd. Strong dielectric loss peak was observed on the samples of Bi 1- x Nd x FeO 3 ( x =0.15) and Bi 1- x Nd x FeO 3 ( x =0.2). Results show that Nd substitution is an effective way to push BiFeO 3 to become microwave absorbing materials with high performance.

La 1− x Ag x MnO 3 perovskites with different doping Ag-content were prepared by the sol–gel method. The electromagnetic characteristics and microwave loss behavior of these ion-doped rare-earth manganites were studied in the 2–18 GHz frequency range. The microstructure and morphology of the samples were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. The complex permittivity spectra, the complex permeability spectra and microwave reflection loss were measured by a microwave vector network analyzer system. The XRD patterns show that the crystalline perovskite main phase ABO 3 is formed and impurity phases disappear when calcined at 1100 °C, and Ag metal as an impurity phase appears when excessive Ag + is doped. The SEM image indicates that many of the La 0.85 Ag 0.15 MnO 3 particles are fiber-like or ellipsoidal. Magnetic loss and dielectric loss coexist and cooperate in microwave attenuation by moderate substitution of Ag + for La 3+ . The microwave absorption property of the La 0.85 Ag 0.15 MnO 3 sample is enhanced with the bandwidth below −10 dB at about 6 GHz and the peak value of reflection loss is near −25.0 dB at the layer thickness of 2 mm.

W-type barium hexaferrites with compositions of Ba 1 Co 0.9 Zn 1.1 Fe 16 O 27 and Ba 0.8 La 0.2 Co 0.9 Zn 1.1 Fe 16 O 27 were synthesized by the sol–gel method. The electromagnetic properties and microwave absorption behavior of these two ferrites were studied in the 2–18 GHz frequency range. The microstructure and morphology of the ferrites were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. The complex permittivity spectra, the complex permeability spectra and microwave reflection loss were measured by a microwave vector network analyzer. The XRD patterns show that the main phase of the Co 2 W ferrite forms without other intermediate phases when calcined at 1200 °C. The SEM images indicate that flake-like hexagonal crystals distribute uniformly in the materials. Both the magnetic and dielectric losses are significantly enhanced by partial substitution of La 3+ for Ba 2+ in the W-type barium hexaferrites. The microwave absorption property of the La 3+ doping W-type hexaferrite sample is enhanced with the bandwidth below −10 dB around 8 GHz and the peak value of reflection loss about −39.6 dB at the layer thickness of 2 mm.