Weakly negative permittivity of MWCNT/TiN/CCTO ternary ceramics sintered in argon and nitrogen atmosphere

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).…”

Low‐loss percolative epsilon‐negative composites derived from the ultra‐low percolation threshold

“…With the AgNWs content increasing as shown in Figure 2B,D, the AgNWs are evenly distributed in the PVDF matrix and further strengthen the percolation networks, which can provide pathways for the transportation of free electrons. [ 31,32 ]…”

“…With the AgNWs content increasing as shown in Figure 2B,D, the AgNWs are evenly distributed in the PVDF matrix and further strengthen the percolation networks, which can provide pathways for the transportation of free electrons. [31,32] Figure 3 shows the dispersion of the permittivity and impedance properties of the AgNWs/PVDF composites. For different AgNWs content, the permittivity response of the composites is completely different, as shown in Figure 3A,B.…”

Epsilon-negative behavior and its capacitance enhancement effect on trilayer-structured polyimide–silica/multiwalled carbon nanotubes/polyimide–polyimide composites

“…17,18 In general, the materials with negative permittivity can be observed in the metacomposites by introducing conductive fillers as carbon materials, metal particles, or fibers. For instance, several studies were devoted to realizing the negative permittivity in carbon composites with different carbon nanostructures, such as carbon nanoparticles, [19][20][21][22] graphene, 23,24 and carbon nanotubes. [25][26][27][28] Meanwhile, some metal particles (e.g., Ni, Fe, Ag, Cu, or Co) and some metal alloy composites were randomly dispersed in an insulating matrix that can also realize the negative permittivity.…”