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Cobalt ferrite–silica–gold nanocomposite (CoFe2O4@SiO2@Au) is synthesized using a new method involving: i) the polyol method for cobalt ferrite nanoparticles (CoFe2O4), ii) the Stober method for silica coating, iii) surface functionalization with 3‐aminopropyl triethoxysilane (APTES), and iv) decoration with gold nanoparticles via tetrakis hydroxy‐methyl‐phosphonium (THPC) reduction. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirm the morphology of the nanoparticles and coatings for the nanocomposites. Ultraviolet–visible (UV–Vis) absorption spectra exhibit plasmon resonance peaks with tuned shifts, discuss in terms of the difference in dielectric permittivity in the core where gold nanoparticles are anchored. Magnetic hysteresis analysis reveals superparamagnetic behavior with reduced saturation magnetization for the nanocomposites. These findings are useful, as superparamagnetic behavior combined with control of plasmonic emission is highly relevant for several magneto‐plasmonic applications. [ABSTRACT FROM AUTHOR]

We report a facile synthesis of MXene/bismuth ferrite (Ti 3 C 2 T x @ BiFeO 3 ) nanocomposites using hydrazine hydrate induced with the hydrothermal method. Preparation of the composite with hydrazine hydrate prevents the formation of Bi 25 FeO 39 inside the matrix. The 25 wt % loading of BiFeO 3 acts as spacers for the multilayer restacking of MXene flakes by retaining the (002) plane. This promotes large dc conductivity with interfacial and defect dipole polarization mechanisms inside the composite material. The thinner M-H loop also indicates the minimal magnetic loss inside the composites. The facile synthesis strategy provides outstanding properties in Ti 3 C 2 T x @ BiFeO 3 composites as two-dimensional multiferroic materials., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

High magnitudes of permittivity with the permeability of the materials help to absorb electromagnetic waves more efficiently. Snoek's limit directly puts a constraint on the enhancement of the permeability of the material. However, the incorporation of the lossy material may help to enhance the permittivity abruptly. In this study, we prepared a FeSi/SiC composite material with the mechanical ball milling method and investigated its enhancement of the dielectric behavior. The bianisotropic nature was observed along with the phase purity in the morphological studies. The Cole-Cole relaxation mechanisms were observed to validate a complex relaxation mechanism with 10 4 times higher dielectric loss in the composite material. The detection of the Warburg capacitance using the impedance technique sheds new light on the ion diffusion mechanism in the metallic composite materials., Competing Interests: The authors declare no competing financial interest.