Experimental realization of tunable negative permittivity in percolative Fe₇₈Si₉B₁₃/epoxy composites

Abstract

Tunable negative permittivity in the radio frequency range has been obtained by percolative Fe78Si9B13/epoxy composites.

Negative permittivity behavior in the carbon/silicon nitride composites prepared by impregnation-carbonization approach

“…In general, metal manifests negative permittivity below the plasma frequency, so the ENG property is mainly obtained in metallic composites up to now, and originates from the plasma oscillation of delocalized electrons in the metallic elements [9,24]. Interestingly, some studies have been devoted to realize the negative permittivity characteristic in carbon-polymer composites recently.…”

“…In 2000, the simultaneously negative permittivity and permeability were achieved in an "artificial" meta-materials composed of periodic metallic wire arrays by Smith et al [7], and the phenomenon of negative refraction was observed in this double negative (DNG) medium [8]. After that, materials with tunable negative electromagnetic parameters have attracted ever-increasing attention [9][10][11][12][13][14][15]. Some "real" random materials consisting of magnetic, dielectric or metallic component have been fabricated to achieve negative permittivity and/or negative permeability in various frequency ranges by adjusting their compositions and microstructures [16][17][18][19][20].…”

Lamellar columnar liquid-crystalline mesophases as a 2D platform for anhydrous proton conduction

“…Likewise, the Jonscher's universal dielectric response law could be verified at high frequencies for all temperatures measured. 18 This feature allowed obtaining the Jonscher exponent, whose value was found to be n = 0.92.…”

“…Likewise, the isoquinoline moiety and the benzene ring are also coplanar with the own pyrazole ring (dihedral angles of 0.3(1)º and 3.1(1)º, respectively). Only the terminal alkyl chains show a major deviation with respect to the benzene group because they R(14,14)iq )] 28 at 173 ºC, and (e) [PdI2(Hpz R (18,18)iq )] 34 at 149 ºC. All images were taken on cooling under crossed polarisers point out of the molecular core in an orthogonal direction ( Figure 3).…”

“…POM microphotographs of the mesophase of (a) [PdCl2(HpzR(16,16)iq )] 25 at 132 ºC, (b) [PdBr2(Hpz R(18,18)py )] 13 at 99 ºC, (c) [PdI2(Hpz R(12,12)py )] 15 at 110 ºC, (d) [PdBr2(Hpz…”