Tunable negative dielectric properties of magnetic CoFe2O4/graphite-polypyrrole metacomposites

Negative Permittivity Behaviors Derived from Dielectric Resonance and Plasma Oscillation in Percolative Bismuth Ferrite/Silver Composites

“…Thus, the phenomenon of low-frequency plasma oscillation occurs. A similar phenomenon has been also reported in other composites. ,, Theoretically, the negative permittivity induced by low-frequency plasma oscillation can be described by the Drude model, , as follows where ω τ is the collision frequency of electrons, n eff is the effective concentration of free electrons, and m eff is the effective mass of electrons. The fitted curve was also in good agreement with the experimental results l (solid lines in Figure b).…”

“…In detail, due to the real part of the permittivity crossing zero, negative permittivity was observed in the frequency range from 915 MHz to 1 GHz, 840 MHz to 1 GHz, and 755 MHz to 1 GHz, respectively. This is an obvious phenomenon of dielectric resonance, which can be described by the Lorentz model, , where Γ L is the damping factor of the Lorentz resonance, ω 0 is the Lorentz resonance frequency, and K is the polarizability under a DC electric field. The detailed fitting parameters are shown in Table .…”

“…In detail, due to the real part of the permittivity crossing zero, negative permittivity was observed in the frequency range from 915 MHz to 1 GHz, 840 MHz to 1 GHz, and 755 MHz to 1 GHz, respectively. This is an obvious phenomenon of dielectric resonance, which can be described by the Lorentz model, 27,37…”

“…A similar phenomenon has been also reported in other composites. 23,37,41 Theoretically, the negative permittivity induced by low-frequency plasma oscillation can be described by the Drude model, 41,42 as follows…”

Hydroxyapatite coatings: a critical review on electrodeposition parametric variations influencing crystal facet orientation towards enhanced electrochemical sensing

“…To mitigate these mechanical and electrical restrictions, HAp is generally coupled as a composite with metallic and metal oxide substrates of Ti, Mg, and carbon-based composites to act as a backbone of sorts in enhancing its mechanical properties 9 and in providing a point of electrical contact and conduction. Nanocomposite coatings are considered an effective strategy in the fabrication of heterogeneous materials 10,11 resulting in improvement in physico-chemical properties, [12][13][14][15][16][17][18] mitigating detrimental degradation, [19][20][21] and in enhancing its applicative aspects towards increased efficacy, [22][23][24][25] in reinforcement, [26][27][28][29] and sustainability. 30 The fabrication of these nanocomposites offers a certain degree of flexibility in their respective field of application.…”