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The dynamics of spin and charge-ordered phases in La1.67Sr0.33NiO4 single crystal have been investigated using high-frequency dielectric spectroscopy. The measurements were carried out in frequencies between 0.156 and 316 MHz and temperatures from 50 to 320 K. The intrinsic part of the response by excluding the Maxwell–Wagner relaxation region is obtained below TSDW ∼ 120 K. The intrinsic frequency-dependent real dielectric constant ɛ′ and conductivity σ′ can be well described in terms of the constant phase element revealing a complex charge-hopping process. Our results are in agreement with the spin-density-wave puddles' picture observed by the scanning micro-x-ray diffraction technique. These demonstrate that high-frequency dielectric spectroscopy can be utilized for investigating the various order phases in other transition metal oxides by considering their intrinsic responses. [ABSTRACT FROM AUTHOR]

Sizable glass formers feature numerous unique properties and potential applications, but many questions regarding their glass transition dynamics have not been resolved yet. Here, we have analyzed structural relaxation times measured as a function of temperature and pressure in combination with the equation of state obtained from pressure–volume–temperature measurements. Despite evidence from previous dielectric studies indicating a remarkable sensitivity of supercooled dynamics to compression, and contrary to intuition, our results demonstrated the proof for the almost equivalent importance of thermal energy and free volume fluctuations in controlling reorientation dynamics of sizable molecules. The found scaling exponent γ = 3.0 and Ev/Ep ratio of 0.6 were typical for glass-forming materials with relaxation dynamics determined by both effects with a minor advantage of thermal fluctuations involvement. It shows that the high values of key parameters characterizing the sensitivity of the glass transition dynamics to pressure changes, i.e., activation volume ΔV and dTg/dP, are not a valid premise for a remarkable contribution of volume to glass transition dynamics. [ABSTRACT FROM AUTHOR]

Simulating the dielectric spectra of solvents requires the nuanced definition of inter- and intra-molecular forces. Non-polarizable force fields, while thoroughly benchmarked for dielectric applications, do not capture all the spectral features of solvents, such as water. Conversely, polarizable force fields have been largely untested in the context of dielectric spectroscopy but include charge and dipole fluctuations that contribute to intermolecular interactions. We benchmark non-polarizable force fields and the polarizable force fields AMOEBA03 and HIPPO for liquid water and find that the polarizable force fields can capture all the experimentally observed spectral features with varying degrees of accuracy. However, the non-polarizable force fields miss at least one peak. To diagnose this deficiency, we decompose the liquid water spectra from polarizable force fields at multiple temperatures into static and induced dipole contributions and find that the peak originates from induced dipole contributions. Broadening our inquiry to other solvents parameterized with the AMOEBA09 force field, we demonstrate good agreement between the experimental and simulated dielectric spectra of methanol and formamide. To produce these spectra, we develop a new computational approach to calculate the dielectric spectrum via the fluctuation dissipation theorem. This method minimizes the error in both the low and high frequency portions of the spectrum, improving the overall accuracy of the simulated spectrum and broadening the computed frequency range. [ABSTRACT FROM AUTHOR]

The conductivity type is one of the most fundamental transport properties of semiconductors, which is usually identified by fabricating the field-effect transistor, the Hall-effect device, etc. However, it is challenging to obtain an Ohmic contact if the sample is down to nanometer-scale because of the small size and intrinsic heterogeneity. Noncontact dielectric force microscopy (DFM) can identify the conductivity type of the sample by applying a DC gate voltage to the tip, which is effective in tuning the accumulation or depletion of charge carriers. Here, we further developed a dual-modulation DFM, which simplified the conductivity type identification from multiple scan times under different DC gate voltages to a single scan under an AC gate voltage. Taking single-walled carbon nanotubes as testing samples, the semiconducting-type sample exhibits a more significant charge carrier accumulation/depletion under each half-period of the AC gate voltage than the metallic-type sample due to the stronger rectification effect. The charge carrier accumulation or depletion of the p-type sample is opposite to that of the n-type sample at the same half-period of the AC gate voltage because of the reversed charge carrier type. [ABSTRACT FROM AUTHOR]

The optical behavior of the square lattices of the hemispherical nanovoids on the surface of the high-refractive-index all-dielectric slabs in the visible range is studied numerically using gallium phosphide as an example. There exist Fano resonances for these metasurfaces for a limited range of thicknesses. The Fano resonances are caused by the interference between the Mie-type scattering resonances of surface pattern elements and the Fabry–Pérot modes of the slabs. The maximum enhancements of the optical Kerr nonlinearity with respect to the bulk material are revealed at the Fano resonances, in particular, for the thinnest nanostructures. Interestingly, no positive correlation between the quality factor and the enhancement of the optical Kerr effect of the metasurface at the Fano resonances is observed. [ABSTRACT FROM AUTHOR]

We report spontaneous symmetry breaking (SSB) phenomena in symmetrically charged binary particle systems under planar nanoconfinement with negative dielectric constants. The SSB is triggered solely via the dielectric confinement effect, without any external fields. The mechanism of SSB is found to be caused by the strong polarization field enhanced by nanoconfinement, giving rise to charge/field oscillations in the transverse directions. Interestingly, dielectric contrast can even determine the degree of SSB in transverse and longitudinal dimensions, forming charge-separated interfacial liquids and clusters on square lattices. Furthermore, we analytically show that the formed lattice constant is determined by the dielectric mismatch and the length scale of confinement, which is validated via molecular dynamics simulations. The novel broken symmetry mechanism may provide new insights into the study of quasi-2D systems and the design of future nanodevices. [ABSTRACT FROM AUTHOR]

The spur reaction, a spatially nonhomogeneous chemical reaction following ionization, is crucial in radiolysis or photolysis in liquids, but the spur expansion process has yet to be elucidated. One reason is the need to understand the role of the dielectric response of the solvating molecules surrounding the charged species generated by ionization. The dielectric response corresponds to the time evolution of the permittivity and might affect the chemical reaction–diffusion of the species in a spur expansion process. This study examined the competitive relationship between reaction–diffusion kinetics and the dielectric response by solving the Debye–Smoluchowski equation while considering the dielectric response. The Coulomb force between the charged species gradually decreases with the dielectric response. Our calculation results found a condition where fast recombination occurs before the dielectric response is complete. Although it has been reported that the primary G-values of free electrons depend on the static dielectric constant under low-linear-energy transfer radiation-induced ionization, we propose that considering the dielectric response can provide a deeper insight into fast recombination reactions under high-linear-energy transfer radiation- or photo-induced ionization. Our simulation method enables the understanding of fast radiation-induced phenomena in liquids. [ABSTRACT FROM AUTHOR]

Polymer dielectrics with excellent capacitive performance are urgently needed in advanced electrical and electronic systems. However, due to the dramatic increase in the conduction loss, the energy density and efficiency of polymers degrade severely at elevated temperatures, limiting their application in harsh environments up to 150 °C. Herein, an all-organic polyurea (PU)/polyetherimide (PEI) blend film is designed to prepare high-temperature polymer dielectric. It is found that carrier traps can be introduced by blending, and the hydrogen bond between PU and PEI increases the trap depth, leading to suppressed leakage current and enhanced breakdown strength, thus improving the energy storage performance. PU/30%PEI exhibits a high discharged energy density of ∼3.74 J/cm3 with an efficiency higher than 90% at 150 °C, which is 78% and 70% higher than pristine PU and PEI, respectively. This work provides a facile strategy to improve the energy storage performance of polymer dielectrics by introducing deep traps through blending. [ABSTRACT FROM AUTHOR]

We experimentally investigate phase shift gained by electromagnetic radiation transmitted through a two-dimensional electron system (2DES) on a dielectric substrate. We systematically examined the dependence of the phase shift on the radiation frequency and 2DES electron density for the GaAs semiconductor substrate. A theoretical approach was developed that found good agreement with experimental results. We demonstrate a practically achievable phase shift of 105 °. Obtained findings pave the way for the design of terahertz devices that can manipulate the radiation phase in a controlled and precise manner. [ABSTRACT FROM AUTHOR]

When using metal–organic frameworks (MOFs) as electric field-dependent sensor devices, understanding their dielectric response is crucial as the orientation of polar groups is largely affected by confinement. To shed light on this at the molecular level, the response to a static field was computationally investigated for two structurally related MOFs, depending on their loading with guest molecules. The pillared-layer MOFs differ in their pillar moiety, with one bearing a rotatable permanent dipole moment and the other being non-polar. Two guest molecules with and without polarity, namely, methanol and methane, were considered. A comprehensive picture of the response of the guest molecules could be achieved with respect to both the amount and polarity of the confined species. For both MOFs, the dielectric response is very sensitive to the introduction of methanol, showing an anisotropic and non-linear increase in the system's relative permittivity expressed by a strongly increasing polarization response to external electric fields scaling with the number of confined methanol molecules. As expected, the effect of methane in the non-dipolar MOF is negligible, whereas subtle differences can be observed for the dipolar response of the MOF with rotatable dipolar linker groups. Taking advantage of these anisotropic and guest-molecule-specific confinement effects may open pathways for future sensing applications. Finally, methanol-induced global framework dynamics were observed in both MOFs. [ABSTRACT FROM AUTHOR]

[001]-textured 0.4P(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3-0.5%MnO2 (Mn-PMN-PZT) ceramics were fabricated by templated grain growth using 2 vol. % BaTiO3 in this paper. Full matrices of dielectric (ɛij), elastic (sij, cij), and piezoelectric (dij) parameters were obtained by the resonance–antiresonance method. The dielectric constant ɛ33T of textured ceramics reaches 2600, which is four times that of random ceramics. Textured Mn-PMN-PZT ceramics exhibit high d33 = 984 pC/N and high k33 = 0.89, which is much larger than d33 = 223 pC/N and k33 = 0.70 of random ceramics. However, ɛ11T of ceramics decreases by about 30% after texturing, and the corresponding shear coupling coefficient k15 also decreases from 0.66 to 0.44, which may be due to the reduction in the angle between spontaneous polarization and transverse direction. Furthermore, the temperature stability of the textured ceramics was evaluated as well. The phase transition temperature TR−T was determined by the impedance method to be 120 °C. The textured Mn-PMN-PZT ceramic shows high temperature stability, which is better than PMN-PT. [ABSTRACT FROM AUTHOR]

Oxygen defects are introduced into PbZr0.5Ti0.5O3 films and their impact on ferroelectric behavior, linear dielectric response (LDR), and nonlinear dielectric response (NDR) is studied. Apart from a notable decrease in both polarization and LDR permittivity, the frequency spectra of LDR exhibit a distinctive loss peak. The peak position varies with temperature and oxygen defect concentration. NDR parameters, including the Rayleigh coefficient (α1), the slope (α2) correlating the imaginary part of permittivity with the ac electric field, and the slope (k) between the real and the imaginary parts of permittivity, demonstrate diverse behaviors in response to temperature and oxygen defect concentration. The similarity in the frequency spectra of tanδ and 1/k reveals the correlation between LDR and NDR induced by the presence of oxygen defects. These observations are attributed to the behavior of the single and composite defects associated with oxygen vacancies. [ABSTRACT FROM AUTHOR]

We determine the surface tension of aqueous electrolyte solutions in contact with non-polar dielectric media using a thermomechanical approach, which involves deriving the stress tensor from the thermodynamic potential of an inhomogeneous fluid. To obtain the surface tension, we calculate both the normal and tangential pressures using the components of the stress tensor, recently derived by us [Y. A. Budkov and P. E. Brandyshev, J. Chem. Phys. 159, 174103 (2023)] within the framework of Wang's variational field theory. Using this approach, we derive an analytical expression for the surface tension in the linear approximation. At low ionic concentrations, this expression represents the classical Onsager–Samaras limiting law. By utilizing only one fitting parameter, which is related to the affinity of anions to the dielectric boundary, we successfully approximated experimental data on the surface tension of several aqueous electrolyte solutions. This approximation applies to both the solution–air and solution–dodecane interfaces, covering a wide range of electrolyte concentrations. [ABSTRACT FROM AUTHOR]

(Bi0.5Na0.5)1−xBaxTiO3 lead-free ferroelectric ceramics were synthesized via the conventional solid-state reaction method. Structural and dielectric properties were investigated as a function of the doping concentration, considering x = 0, 2, 5, 8, 10, 12, 16, and 18 at. % Ba. The structural analyses were carried out from the x-ray diffraction technique, including the Rietveld refinement method, and Raman spectroscopy. Results confirmed the formation of the perovskite structure, revealing different crystalline symmetries, depending on the Ba2+ concentration: the single rhombohedral ferroelectric phase (R3c) for x = 0 and 2 at. %; coexistence of both rhombohedral ferroelectric (R3c) and tetragonal antiferroelectric (P4bm) phases for x = 5 at. % Ba; the single tetragonal antiferroelectric phase (P4bm) for x = 8 at. % Ba; coexistence of two tetragonal phases (antiferroelectric P4bm and ferroelectric P4mm) for x = 10 at. % Ba; and the single tetragonal ferroelectric phase (P4mm) for x = 12, 16, and 18 at. % Ba. The characteristics of the phases' transition, investigated from dielectric analysis, revealed the presence of two dielectric anomalies, which indeed have been associated to different phases' transitions, one of them showing relaxor-like characteristics. The obtained results offer new insights for a better understanding on the features of the phase diagram for the studied ceramic system, according to the different observed crystalline symmetries (ferroelectric and antiferroelectric) in a very wide doping concentration. In the light of the obtained results, a new phase diagram has been proposed considering a wider compositional range than those reported in the literature. [ABSTRACT FROM AUTHOR]

Continuum- or discrete-polarizable models for the study of optoelectronic processes in embedded subsystems rely mostly on the restriction of the surrounding electronic dielectric response to its low frequency limit. Such a description hinges on the assumption that the electrons in the surrounding medium react instantaneously to any excitation in the central subsystem, thus treating the environment in the adiabatic limit. Exploiting a recently developed embedded GW formalism with an environment described at the fully ab initio level, we assess the merits of the adiabatic limit with respect to an environment where the full dynamics of the dielectric response are considered. Furthermore, we show how to properly take the static limit of the environment's susceptibility by introducing the so-called Coulomb-hole and screened-exchange contributions to the reaction field. As a first application, we consider a C60 molecule at the surface of a C60 crystal, namely, a case where the dynamics of the embedded and embedding subsystems are similar. The common adiabatic assumption, when properly treated, generates errors below 10% on the polarization energy associated with frontier energy levels and associated energy gaps. Finally, we consider a water molecule inside a metallic nanotube, the worst case for the environment's adiabatic limit. The error on the gap polarization energy remains below 10%, even though the error on the frontier orbital polarization energies can reach a few tenths of an electronvolt. [ABSTRACT FROM AUTHOR]

Current–voltage characteristics, space- and time-resolved optical emission spectroscopy, and 1D fluid modeling are used to examine the effect of dual-frequency sheath oscillations on the ion and electron transport in dielectric barrier discharges sustained by a combination of low frequency (LF, 50 kHz, 650 V) and radiofrequency (RF, 5.3 MHz, 195 V) voltages, exhibiting the α-to-γ mode transition. On one hand, when polarities of the LF and RF voltages are opposite, an electric field near the LF cathode (due to LF cathode sheath) drives the secondary electrons to the plasma bulk and an opposite electric field between the sheath edge and the LF anode attracts the electrons toward the LF cathode (to maintain quasi-neutrality in the plasma bulk). At the sheath edge, electrons become trapped and ions drift toward the cathode and the anode simultaneously according to their position in the gap. On the other hand, when the RF voltage has the same polarity as the LF voltage, the total applied voltage increases and this yields to enhanced production of electrons and ions in the sheath. To maintain quasi-neutrality in the bulk, the electric field along the gap exhibits the same polarity as the one in the sheath, allowing electrons created in the sheath to be evacuated toward the LF anode. The behavior of the LF cathode is, therefore, controlled by the LF sheath, and, thus, by the LF voltage amplitude, while the behavior in the bulk and at the anode alternates on the time scale of the RF voltage. [ABSTRACT FROM AUTHOR]

A frequency-dependent dielectric constant characterizes the dielectric response of a medium and also represents the time scale of system's collective dynamics. Although it is valuable not only academically but also practically for developing advanced devices, getting the value of a solution at the interface with a solid or electrode surface is challenging both experimentally and computationally. Here, we propose a computational method that imitates the dielectric spectroscopy and AC impedance measurement. It combines a time-dependent voltage applied molecular dynamics simulation with an equivalent circuit representation of a system composed of a solution confined between two identical electrodes. It gives the frequency-dependent dielectric constants of the bulk solution and the interface simultaneously. Unlike the conventional method, it does not require computation of a dipole autocorrelation function and its Fourier transformation. Application of the method on a system of water confined between polarizable Pt electrodes gives the static dielectric constant and the relaxation time of the bulk water in good agreement with previous simulation results and experimental values. In addition, it gives a much smaller static dielectric constant at the interface, consistent with previous observations. The outline of the dielectric dispersion curve of the interface seems similar to that of the bulk, but the relaxation time is several times faster. [ABSTRACT FROM AUTHOR]

In this paper, the high-quality factor mullite microwave dielectric ceramic is employed to introduce in dielectric resonator antenna (DRA). The microwave dielectric properties of ɛr ∼ 5.8, Q × f ∼ 31 240 at 9.66 GHz, and loss tangent tanδ = 1/Q ∼ 2.7 × 10−4 can be obtained by the solid-state reaction method in mullite microwave dielectric ceramic sintered at 1700 °C. On this basis, the resonant modes of the proposed broadband high-gain rectangular DRA are analyzed by using a dielectric waveguide theoretical model and the antenna performance is evaluated by a commercial CST Microwave Studio 2021® software. It has been found that the proposed rectangular DRA can provide a broad bandwidth of 35.9%, a maximum gain of 10 dBi at 3.61 GHz, and a radiation efficiency of 90% in the range of 3.13–4.42 GHz. For demonstration, adequate consistency between the simulation results and the measurement results was achieved. The proposed DRA has great application potential and value in 5G communication scenarios requiring wideband and high-gain antenna. [ABSTRACT FROM AUTHOR]

Two-dimensional germanium is considered a promising new channel material to replace silicon owing to its lower effective mass and larger electron–hole mobility. To investigate the transport characteristics of single-layer germanane transistors with gate lengths (Lg) below 5 nm, we utilize an ab initio quantum transport methodology. It was found that the n-type germanane transistors having Lg of 3 and 5 nm satisfy the International Technology Roadmap for Semiconductors (ITRS) requirements for the on-state current (Ion), effective delay time, and power-delay products of high-performance (HP) devices. Notably, by introducing a negative capacitive (NC) dielectric layer, the p-type germanane transistor having an Lg of 5 nm is almost able to meet the ITRS demands for HP devices. Despite reducing the gate length to 2 nm through the incorporation of the NC dielectric layer, the on-state currents for both n-type and p-type still satisfy approximately 80% of the ITRS standard. Therefore, monolayer germanane presents promising potential as a channel material in a sub-5 nm scale for HP applications. [ABSTRACT FROM AUTHOR]

Dielectric interfaces are crucial to the behavior of charged membranes, from graphene to synthetic and biological lipid bilayers. Understanding electrolyte behavior near these interfaces remains a challenge, especially in the case of rough dielectric surfaces. A lack of analytical solutions consigns this problem to numerical treatments. We report an analytic method for determining electrostatic potentials near curved dielectric membranes in a two-dimensional periodic "slab" geometry using a periodic summation of Green's functions. This method is amenable to simulating arbitrary groups of charges near surfaces with two-dimensional deformations. We concentrate on one-dimensional undulations. We show that increasing membrane undulation increases the asymmetry of interfacial charge distributions due to preferential ionic repulsion from troughs. In the limit of thick membranes, we recover results mimicking those for electrolytes near a single interface. Our work demonstrates that rough surfaces generate charge patterns in electrolytes of charged molecules or mixed-valence ions. [ABSTRACT FROM AUTHOR]

Optical second harmonic generation (SHG) can be employed to characterize the passivation quality of semiconducting material interfaces. The interface electric field (EDC) related to the existing charges at and near the interface, including the fixed oxide charges Qox, gives rise to the electric field induced second harmonic phenomenon. In this paper, we calibrate the SHG response for EDC measurement, using Al2O3/SiO2/Si(100) samples with different Qox. To perform this calibration, SHG and capacitance-voltage measurements (to access the electrical field of the samples) were made. The experimental results match well the simulated calibration curve, proving the potential of the SHG as stand-alone characterization technique for dielectric stacks on Si. [ABSTRACT FROM AUTHOR]

Electromagnetic metasurfaces can achieve effective control of electromagnetic waves and achieve effects such as blocking, enhancing, reflecting, transmitting, or deflecting electromagnetic waves, possessing electromagnetic properties that go beyond traditional materials. Existing research indicates that the dielectric substrate of metasurfaces has a significant impact on their electromagnetic properties. Increasing the substrate thickness will be beneficial for expanding the impedance bandwidth of the metasurface, and changes in dielectric constant will also have some impact on the operating frequency and bandwidth of the metasurface. A metasurface based on an air substrate was proposed through the research of dielectric materials. In addition, an ultrawideband, miniaturized, and high-gain metasurface antenna based on an air substrate is designed. The overall size of the designed antenna is 0.5λL × 0.5λL (where λL represents the wavelength at the lowest working frequency in free space). The measured results indicate that the proposed antenna exhibits a −10 dB impedance bandwidth of 74.3% (2.53–5.52 GHz) and a peak boresight gain of 10.1 dBi. [ABSTRACT FROM AUTHOR]

Measurement of high-temperature physical properties at microwave frequency is important to interpret the heating behavior of NiO observed in the author's previous studies. In this study, the impedance (4 Hz–5 MHz) and permittivity [at the microwave frequency (2.45 GHz)] of NiO powder particles were measured from room temperature (RT) to 800 °C. At high frequency above 100 kHz, the conductivity is almost independent of temperature up to a certain temperature (Ti). Above Ti, the conductivity showed a strong positive dependence on the temperature. In this region, the apparent activation energy is determined to be 0.51 eV, which is close to that of the previously reported large polaron transport mechanism (band-like conduction). It was also shown that the conductivity increased linearly with frequency and that a dielectric conductivity relation (σ = ωε″) holds, which is different from the hopping mechanism of the small polaron. Considering these results, it was understood that the temperature increase occurred preferentially in the microwave E-field. The slow increase from the room temperature is due to a small but finite dielectric loss at room temperature, and because of the low conductivity, induction current is not effectively generated in the H-field. On the other hand, after a certain time, the temperature rises to reach the large temperature-dependent conductivity, and then, a significant temperature rise occurs. [ABSTRACT FROM AUTHOR]

Dynamic responses of copper titanates to alternating electric fields with different strengths are characterized in terms of dielectric spectrums. This work extends the introduction of quasipolaron surface polarization (QSP). A collective of quasipolarons pinned at grain surfaces is involved in the electric polarization, which is confirmed by the quadratic polarization–permittivity relation. Because electric polarization is a macroscopic quantum effect, the QSP is described in terms of the density of states (DOS). As a sign of reverse ferroelectricity, dielectric hysteresis loops of reverse-S shape reveal that the characteristic remnant polarization is proportional to the DOS ratio of quasipolaron surface excited to ground states. Although the DOS of the surface ground state is dependent on the mole ratio of quasipolaron quantity, both the DOS and the energy levels of surface excited states show the intrinsic angular-frequency dependence in a power function manner. [ABSTRACT FROM AUTHOR]

The dependence of the dielectric permittivity of ferroelectric materials on electric field magnitude impacts the performance of ferroelectric devices. In a ferroelectric generator, a shock wave travels through the ferroelectric element and depolarizes it, and surface charges are released from the element electrodes, resulting in the generation of a megawatt power level for several microseconds. The dielectric properties of the compressed and uncompressed zones of the ferroelectric element affect the generated voltage and energy. The results of previous studies indicate that the low-field dielectric permittivity of poled Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 (PZT 95/5) ferroelectrics in the uncompressed zone differs significantly from the high-field permittivity. Herein, the results are presented from the experimental investigation of the high-field permittivity of poled uncompressed PZT 95/5 ferroelectric ceramics and films, PZT 52/48 ferroelectric ceramics, and rhombohedral 0.27Pb(In1/2Nb1/2)O3–0.47Pb(Mg1/3Nb2/3)O3–0.26PbTiO3 (0.27PIN-PMN-0.26PT) and 0.68Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (0.68PMN-0.32PT) ferroelectric single crystals. The dependences of the permittivity on the electric field were determined using a pulsed electric field ranging from 0.1 to 10 kV/mm. The data indicate that the application of a pulsed high electric field results in a fourfold increase in the relative permittivity of PZT 95/5 ceramics and films over the small signal value (from 300 to 1200), and a threefold increase in the permittivity of single-domain [111]c cut and poled 0.27PIN-PMN-0.26PT crystals (from 700 to 2100), while a high electric field does not have a significant impact on the permittivity of PZT 52/48 ceramics or 0.27PIN-PMN-0.26PT and 0.68PMN-0.32PT crystals cut and poled in the domain engineered [001]c or [011]c direction. [ABSTRACT FROM AUTHOR]

We present a complete calculation, fully accounting for quantum effects and for molecular flexibility, of the first dielectric virial coefficient of water and its isotopologues. The contribution of the electronic polarizability is computed from a state-of-the-art intramolecular potential and polarizability surface from the literature, and its small temperature dependence is quantified. The dipolar polarizability is calculated in a similar manner with an accurate literature dipole-moment surface; it differs from the classical result both due to the different molecular geometries sampled at different temperatures and due to the quantization of rotation. We calculate the dipolar contribution independently from spectroscopic information in the HITRAN2020 database and find that the two methods yield consistent results. The resulting first dielectric virial coefficient provides a complete description of the dielectric constant at low density that can be used in humidity metrology and as a boundary condition for new formulations for the static dielectric constant of water and heavy water. [ABSTRACT FROM AUTHOR]

We introduce a simple cutoff-based method for precise electrostatic energy calculations in the molecular dynamics (MD) simulations of point-particle systems. Our method employs a theoretically derived smooth pair potential function to define electrostatic energy, offering stability and computational efficiency in MD simulations. Instead of imposing specific physical conditions, such as dielectric environments or charge neutrality, we focus on the relationship represented by a single summation formula of charge-weighted pair potentials. This approach allows an accurate energy approximation for each particle, enabling a straightforward error analysis. The resulting particle-dependent pair potential captures the charge distribution information, making it suitable for heterogeneous systems and ensuring an enhanced accuracy through distant information inclusion. Numerical investigations of the Madelung constants of crystalline systems validate the method's accuracy. [ABSTRACT FROM AUTHOR]

At present, optical anapole resonances in nanostructures have attracted increasing attention due to the strong field confinement and substantially suppressed scattering. This study provides the results of three-dimensional finite-difference time-domain simulations exhibiting the possibility of the anapole state in high refractive index dielectric nanohole array metasurfaces having different profiles of the holes (square, hexagon, and octagon). Behavior of the effective optical Kerr nonlinearity of the metasurfaces in the vicinity of the anapole state is investigated. Depending on the geometry, the absolute value of the effective nonlinear Kerr coefficient of the metasurface may be up to three orders of magnitude greater than that of the unstructured film. A square transverse section of the nanohole is preferable for the optical Kerr effect in the holey metasurfaces. The effect of the random rotation of the square holes representing the metasurface irregularity on the optical nonlinearity is examined. As a result, the dielectric nanohole array metasurfaces display a concrete possibility to have the anapole state with large enhancement of the optical nonlinearity. [ABSTRACT FROM AUTHOR]

Ionizable copolymers assembly in solutions is driven by the formation of ionic clusters. Fast clustering of the ionizable blocks often leads to the formation of far-from equilibrium assemblies that ultimately impact the structure of polymer membranes and affect their many applications. Using large-scale atomistic molecular dynamics simulations, we probe the effects of electrostatics on the formation of ionizable copolymer micelles that dominate their solution structure, with the overarching goal of defining the factors that control the assembly of structured ionizable copolymers. A symmetric pentablock ionizable copolymer, with a randomly sulfonated polystyrene center tethered to polyethylene-r-propylene block, terminated by poly(t-butyl styrene), in solvents of varying dielectric constants from 2 to 20, serves as the model system. We find that independent of the solvents, this polymer forms a core–shell micelle with the ionizable segment segregating to the center of the assembly. The specific block conformation, however, strongly depends on the sulfonation levels and the dielectric constant and the polarity of the solvents. [ABSTRACT FROM AUTHOR]

The domain reversal dynamics of the pristine and 10 wt. % BiFeO3 nanoparticle-embedded P(VDF-TrFE) (polyvinylidene fluoride-trifluoroethylene) flexible ferroelectric membranes were investigated. A scaling relation of A∝fαE0β relevant to the domain reversal dynamics was eventually determined. The pristine P(VDF-TrFE) flexible membrane takes the form of A∝f0.04077E00.39748 in stage III of high electric fields. Nevertheless, for BiFeO3-embedded P(VDF-TrFE) [BFO/P(VDF-TrFE)] flexible membranes, the relations are developed as A∝f−0.3326E02.74911 in the low electric fields of stage I and as A∝f0.04309E01.04872 in stage III separately. The negative α indicates that more and more domain reversal lags behind the alternating periodic electric field in stage I. Instead, in stage III, the positive α indicates that most domain reversals can occur anytime whatever the alternating speed of electric fields is. Analogously, the positive β indicates that at any selected frequency, domains can flip at an external electric field. Abnormally, for the pristine P(VDF-TrFE) membrane, the scaling relation in the first E0 stage is broken, reflecting only dielectric contributions this time. The dynamic scaling data are significant for the micromechanism accomplishments of copolymers and for the designs of flexible electric devices. [ABSTRACT FROM AUTHOR]

Dielectric energy storage capacitors offer great potential in pulsed power devices due to the high power density and fast charging-discharging rate. Designing a host material with high field-induced polarization is of importance for developing dielectric energy storage materials via further composition modulation. In this paper, we compare the microstructure, dielectric, and ferroelectric properties as well as the energy storage performance of samples K1/2Bi1/2TiO3(KBT), 75KBT-25BiFeO3 (KBTF25), and 88KBT-12Bi0.85Nd0.15FeO3 (KBNTF12) in detail. It is found that, among three samples, sample KBNTF12 possesses the most complex local structure coexisting of a four-distortions with different polarities; meanwhile, sample KBNTF12 behaves as a strong relaxor, thus giving a high field-induced polarization. Besides, sample KBNTF12 realizes the highest electric breakdown strength Eb among three samples, which is resorted to the highest resistivity of grain boundary. Highest ΔP and Eb of sample KBNTF12 among three samples render it achieve ultrahigh stored energy density Ws of 6.94 J/cm3, high recoverable energy density Wr of 5.23 J/cm3, and high efficiency η of 75.4%. Our work suggests that 88KBT-12BNF binary composition be an optimal candidate for dielectric energy storage ceramics. [ABSTRACT FROM AUTHOR]

This paper investigates near-interfacial charge trapping effects in graphene field-effect transistors with high-K gate dielectrics. Experimental and model-based analysis elucidates the impact of trapped charge on the transport properties of graphene. Landauer formalism is applied to correlate trapping-enhanced charged impurity scattering to degradation in conductivity and mobility. The analysis shows a significant reduction in conductivity and mobility with a transition toward the dominance of charge impurity scattering as evidenced by their dependence on the sheet carrier density. Moreover, we quantify the impact of trapped charge buildup on the carrier backscattering mean free path associated with charged impurities. This work provides new insights into the impact of charge trapping toward the development of logic, memory, and neuromorphic devices based on graphene and other low-dimensional materials and ultrascaled high-K dielectrics. [ABSTRACT FROM AUTHOR]

The search for a high- κ dielectric material that combines a high dielectric constant (ϵ ′ ) and low dielectric loss is very crucial because of its widespread use in gate dielectrics to avoid the leakage current that arises due to continued miniaturization of present SiO 2 -based metal-oxide semiconductor field-effect transistor devices. RCrO 3 (R is a rare-earth ion) materials have been at the center of interest because of their intriguing ferroelectric and magnetic properties, as well as their room-temperature colossal dielectric constant (CDC) values. Although CDC (ϵ ′ ∼ 10 4) in RCrO 3 materials is quite common, it is unsuitable for device applications since it is associated with a larger dielectric loss value (tan δ ∼ 7 at 11 kHz). Here we have focused on polycrystalline DyCrO 3 , prepared using multiple synthesis techniques, and thoroughly investigated the origin and tuning of the various dielectric relaxations that give rise to CDC and large dielectric loss values. A clear understanding of the origin of dielectric relaxations enables us to design a specially synthesized DyCrO 3 (SPS-DCO) in which the extrinsic dielectric relaxations driven large dielectric loss values can be completely suppressed and which is found to be associated with optimized high- κ dielectric properties [ ϵ ′ ∼ 130 , tan δ ∼ 0.06 , and temperature coefficient of dielectric constant (TC ϵ) ∼ 2280 ppm/K at 11 kHz, 300 K]. The only remaining intrinsic Debye-type dielectric relaxation in SPS-DCO arises due to electric-field-assisted charge hopping among various valences of Cr (investigated using x-ray photoelectron spectroscopy) that presently limits the lowest attainable loss value. [ABSTRACT FROM AUTHOR]

Luneburg lens is traditionally a spherical dielectric with centro-symmetric and graded refractive index, which has been widely applied in civilian and military fields due to its outstanding abilities of focusing or collimating electromagnetic waves. However, the existing designs of Luneburg lens generally suffer from the disadvantages of bulkiness, complex fabrication process, and limited scanning angles, etc. Herein, a planar metasurface that could mimic the planar Luneburg lens is designed by utilizing the addition theorem. It has been experimentally verified that the Luneburg-like lens has large and continuous scanning angles from − 52 ° to 52° at a frequency of 10 GHz if an excitation antenna is moved along a straight line. Besides, the total thickness of the proposed lens is only 3 mm and it has the advantages of low cost, ease of fabrication, as well as being isolated from the feeder. As a result, the proposed Luneburg-like lens has great potential values of being flexibly applied in numerous fields. [ABSTRACT FROM AUTHOR]

In this study, analytical models for space charge limited current (SCLC) transport in a porous (or disordered) trap-limited dielectric cylindrical configuration are developed. The method used in this paper is first verified by reproducing the well-known analytical results for planar cases developed decades ago based on the traditional approach. By considering the porous solid as a fractional object characterized by a parameter α ≤ 1 , we formulate its fractional capacitance and determine the SCLC transport by using the transit time approach. At α = 1 , it will recover the well-known Mott–Gurney law and Mark–Helfrich law for trap-free and trap-limited cases, respectively. For cylindrical geometry, our findings show an analytical form that is not available from the traditional methods. We anticipate that the proposed analytical model will serve as a useful tool for characterizing the current–voltage measurements in SCLC transport in dielectric breakdown and organic electronics, where spatial porosity of the materials is inevitable. The introduced fractional parameter α extracted from such characterization can facilitate the quantitative determination of the relationship between spatial porosity and charge mobility. [ABSTRACT FROM AUTHOR]

The solid solution Ba 1 − x Sr x TiO 3 (BSTO) displays dielectric response that is highly tunable, while also exhibiting low losses in a broad frequency regime, including the microwave band. Therefore, there is a need for a better understanding of the influence of the BSTO microstructure on its relaxor properties and performance in a variety of technological applications. Since the local polarization in BSTO is strongly dependent on composition, so is its response to an applied AC field. In this work, we have adopted a phase field method to study the frequency-dependent dielectric response of this system while accounting for the local fluctuations in the solid-solution composition. By utilizing a thermodynamic potential that includes spatial dependence on the averaged Sr content, we connected relaxor-like features in the dielectric dispersion to local spatial inhomogeneities, such as average size of Sr- or Ba-rich regions, across a wide range of temperatures. These results show that the adopted simple coarse-grained approach to the relaxor problem is sensitive enough to reveal correlations between the frequency and temperature dependence of the dielectric response and modulations in the material morphology and microstructure. [ABSTRACT FROM AUTHOR]

The dynamic response of dielectric elastomers is widely used in many functional devices, but current research has neglected the effect of varying dielectric permittivity on their dynamic oscillations and stability. This paper studies the thin-walled dielectric balloon in which the stretch-dependent dielectric permittivity is considered. We obtain the dynamic equation of motion by Hamilton's principle. Based on the principle of no energy dissipation in conservative systems, we establish energy conservation at the maximum stretching position and at the initial moment, then we investigate the stability in the dynamic case. It is found that a stretch-related dielectric permittivity can increase the critical electric field of the balloon and can also change the mode of electric field instability and modulate the critical stretch value. In the dynamic case, the stretch-dependent permittivity increases the critical electric field by 4 % when the balloon is only subjected to electric force; moreover, it increases the critical stretch value by 316.68 % by changing the unstable mode from pull-in instability to snap-through instability. It is hoped that this work will provide new thinking in designing functional devices by using the dynamical response and stability of dielectric elastomers. [ABSTRACT FROM AUTHOR]

The discharge mode of a multi-hollow dielectric barrier discharge (MHDBD) plays an important role in the treatment outcomes but has not been well studied. In this study, an MHDBD is fabricated to investigate the discharge characteristics and the mode transition from both electric and optical perspectives. Three discharge modes are recognized with the increase of the applied voltages: inner-wall discharge, mode A (12–13.3 kV); hole-inside discharge, mode B (13.4–14.3 kV); and hole-surface hybrid discharge, mode C (≥14.4 kV). It is found that the transferred charges and the produced reactive species increase slowly in mode A, then augment rapidly in mode B, and finally saturate in mode C. The micro-process of the mode transition shows that the discharging domain initiates at the edge of the hole (mode A), subsequently extends toward the center (mode B), and ultimately extends beyond the hole boundary (mode C). To further understand these transitions, finite element simulations and an equivalent circuit model of MHDBD are conducted, which reveal enhanced discharge strength and discharge area as the system progresses from mode A to mode B and C. The speculative mechanism of a mode transition involves the variation of the electric field distribution and the resulting acceleration of the electrons, and the following collision responses. Additionally, the effect of pulse frequency and hole diameter of the MHDBD on the mode transition conditions is also investigated, and the results show that higher frequencies are easier to prone mode transition, while large holes have fewer discharge modes. [ABSTRACT FROM AUTHOR]

The microwave-to-plasma energy conversion efficiency and the ease of plasma self-ignition are critical factors affecting the applications for microwave plasma sources (MPSs). This study presents a novel MPS utilizing dielectric wedges for self-ignition and improved energy conversion. Firstly, we crafted a dielectric wedge with a gradient refractive index, guiding the electric field from air to dielectric materials and facilitating microwave propagation along the dielectric in a waveguide. Through electromagnetic simulation, we explored how the size and permittivity of the dielectric wedge affect the electric field distribution. Then, the MPS based on the dielectric wedge was designed. In this configuration, a dielectric tube encloses the discharge tube, connecting to dielectric wedges to guide electromagnetic waves to the plasma. We analyzed the MPS performance using the Drude model, evaluating microwave energy conversion efficiency across various electron densities and collision frequencies. The results were compared with a commonly used MPS based on a tapered waveguide, demonstrating the proposed MPS has wider applicability across different operation conditions. Finally, experiments under low pressures were conducted using various gases, showing an average energy conversion efficiency of approximately 40% higher than the tapered waveguide MPS. The experiments also indicate the proposed MPS has a greater capability of self-ignition at lower power levels. These findings highlight the efficacy of incorporating dielectric wedges to enhance MPS performance, making it conducive for broader industrial applications. [ABSTRACT FROM AUTHOR]

Perovskite structural LiBaF 3 ceramics with excellent microwave dielectric properties were synthesized using traditional solid-state method. By regulating the sintering temperatures from 600 °C to 675 °C, LiBaF 3 ceramics exhibit tunable dielectric constant (ε r) from 12.42 to 13.72, adjustable Q × f value from 55000 GHz to 73000 GHz, and regulable temperature coefficient of resonance frequency (τ f) from −36.78 ppm/°C to −34.68 ppm/°C. The properties are strongly associated with the density, and can be further optimized by 0.5 wt%TiO 2 addition (ε r = 14.43, Q × f = 56000 GHz, τ f = -1.26 ppm/°C). The LiBaF 3 ceramics also exhibit excellent compatibility with Ag and Al electrodes. Furthermore, relationships between multiscale structures and microwave dielectric properties of the ceramics were revealed. Oxidation behaviors between LiBaF 3 and O 2 would result in the lattice shrinkage, the introduction of defect level, the decrease of bandgap and density, and then deteriorating the microwave dielectric properties. All the findings make the LiBaF 3 ceramic a promising candidate for ULTCC application, and may facilitate the development of other novel microwave dielectric materials. [ABSTRACT FROM AUTHOR]

ABSTRACT Cold atmospheric plasma‐activated hydrogel (PAH) exhibits excellent loading and slow‐release capacity for plasma‐generated reactive species. In this study, plasma‐activated pluronic F127 hydrogel (PAH‐PF127) was obtained using surface dielectric barrier discharge (SDBD), and the anticancer effects of PAH‐F127 synergies with the clinical drug paclitaxel (PTX) were investigated. The results indicated that PAH‐PF127 could load plasma‐generated long‐lived reactive species efficiently, and in vitro research revealed that PAH‐PF127 exerts significant anticancer effects by inducing intracellular oxidative stress, and synergies with 50 μg/mL (low‐dose) PTX could easily replace 200 μg/mL (high‐dose) PTX alone. These results suggested that PAH‐PF127 has the potential to address the toxic side effects of high‐dose drugs and expand the application of plasma technology in anticancer treatment. [ABSTRACT FROM AUTHOR]

The dynamical Franz-Keldysh effect, indicative of the transient light-matter interaction regime between quantum and classical realms, is widely recognized as an essential signature in wide bandgap condensed matter systems such as dielectrics. In this theoretical study, we applied time-resolved transient absorption spectroscopy to investigate ultrafast optical responses in graphene, a zero-bandgap system. We observed in the gate-tuned graphene that the massless Dirac materials notably enhance intraband light-driven transitions, significantly leading to the giant dynamical Franz-Keldysh effect compared to the massive Dirac materials, a wide bandgap system. In addition, employing the angle-resolved spectroscopy, it is found that the unique polarimetry orientation, i.e., perpendicular polarizations for the pump and the probe, further pronounces the optical spectra to exhibit the complete fishbone structure, reflecting quantum pseudospin natures of Dirac cones. Our findings expand the establishment of emergent transient spectroscopy frameworks into not only zero-bandgap systems but also pseudospin-mediated quantum phenomena, moving beyond dielectrics. [ABSTRACT FROM AUTHOR]

In this Letter, we demonstrate heteroepitaxial α-Ga2O3 MOSFETs using an aluminum scandium nitride (AlScN) ferroelectric gate stack. Owing to ferroelectric effects, α-Ga2O3 MOSFETs with the AlScN/HfO2 gate stack (FGFET) exhibited enhanced electrical performance compared with a HfO2 gate dielectric (IGFET) for variable gate–drain lengths (10, 15, 20 μm). A remnant polarization value of the AlScN deposited on a HfO2 layer was measured to be about 30 μC/cm2. The subthreshold swing (SS) and field-effect mobility (μFE) of IGFET was extracted at 1814 mV/dec and 13.9 cm2/V s, respectively. However, the FGFET exhibits a reduced SS of 552 mV/dec with enhanced μFE of 42.7 cm2/V s owing to the negative capacitance of the ferroelectric AlScN. Furthermore, a lateral figure-of-merit of 17.8 MW/cm2 was achieved for the FGFET, far surpassing the 8.3 MW/cm2 of the IGFET. The proposed ferroelectric AlScN/HfO2 stack can be a promising gate structure for improving both transfer and breakdown characteristics in heteroepitaxial α-Ga2O3 power devices. [ABSTRACT FROM AUTHOR]

Recently through the synergetic utilization of triboelectrification, electrostatic induction, and electrostatic discharge, a novel dual‐functional triboelectric nanogenerator (DF‐TENG) has been developed, which can not only generate a motion‐responsible alternating current/ direct current output but also provide a higher performance compared to traditional TENGs. However, further improvements in performance and lifespan are crucial and remain challenging for the future large‐scale application of this new‐type TENG. Herein, a novel bioinspired self‐lubricating prototype is presented (BS‐TENG), which employs a porous polyurethane (PU) matrix impregnated with a low‐viscosity dielectric lubricant. In response to external mechanical stimuli, the BS‐TENG can "secrete" pre‐stored lubricant to partially fill micro‐gaps between tribo‐layers, thus forming self‐lubrication. This self‐lubricating mechanism not only elevates the electrostatic discharge threshold between tribo‐layers to maximize charge accumulation, thereby facilitating efficient energy release through electrostatic discharge for enhanced power output, but also significantly reduces material abrasion and realizes superior output durability. Benefiting from this effect, the BS‐TENG delivers an average power density of up to 4.6 W m−2, with extraordinary stability to retain 99% of its initial output even after over 60 000 cycles. This work provides a straightforward and effective strategy for realizing high‐performance and long‐stability TENGs, paving the way for their practical applications. [ABSTRACT FROM AUTHOR]

We consider a homogeneous electromagnetic material enclosing a bounded C2$C^2$‐domain with a small dielectric inclusion. We derive a rigorous asymptotic expansion of the eigenvalues of the Maxwell operator as the diameter of the inclusion goes to zero. [ABSTRACT FROM AUTHOR]

Recent advancements in phase‐change memory (PCM) technology have predominantly stemmed from material‐level designs, which have led to fast and durable device performances. However, there remains a pressing need to address the enormous energy consumption through device‐level electrothermal solutions. Thus, the concept of a 3D heater‐all‐around (HAA) PCM fabricated along the vertical nanoscale hole of dielectric/metal/dielectric stacks is proposed. The embedded thin metallic heater completely encircles the phase‐change material, so it promotes highly localized Joule heating with minimal loss. Hence, a low RESET current density of 6–8 MA cm−2 and operation energy of 150–200 pJ are achieved even for a sizable hole diameter of 300 nm. Beyond the conventional 2D scaling of the bottom electrode contact, it accordingly enhances ≈80% of operational energy efficiency compared to planar PCM with an identical contact area. In addition, reliable memory operations of ≈105 cycles and the 3‐bits‐per‐cell multilevel storage despite ultrathin (<10 nm) sidewall deposition of Ge2Sb2Te5 are optimized. The proposed 3D‐scaled HAA‐PCM architecture holds promise as a universally applicable backbone for emerging phase‐change chalcogenides toward high‐density, ultralow‐power computing units. [ABSTRACT FROM AUTHOR]

Core-shell structured fine grain dielectrics, featured with high dielectric constant and wide temperature stability, are essential for the production of high-end MLCCs. In this work, the core-shell structured 100BaTiO 3 - x BaO-2.4MgO-1.0ZrO 2 -0.03MoO 3 -2.25Y 2 O 3 -0.3MnO 2 -2.0SiO 2 (x = 0.5, 1.0, 1.5, 2.0, 3.0, 4.0) ceramics were prepared and the effects of BaO additions on the microstructure and dielectric properties were studied. The resulting ceramics exhibited fine grains (average size 280–300 nm) and demonstrated a high dielectric constant (>1780). Notably, the core-shell structure of the ceramics was affected by the BaO content, with the core volume gradually increasing as the BaO addition grew. This adjustment in composition was found to enhance the temperature stability and reliability of the materials. When the BaO addition reaches 4.0 mol%, the values of Δ C 150 / C 25 °C were effectively suppressed from −22 % to −10.3 % to meet the X8R specification, and the insulation resistivity increased by more than an order of magnitude, reaching a maximum of 11.6 × 1012 Ω m. Our findings highlight the potential of BaO as an effective additive for enhancing the dielectric properties of core-shell structured fine grain dielectrics for high-end MLCCs. [ABSTRACT FROM AUTHOR]

Gate dielectrics for gallium nitride (GaN) high electron mobility transistor (HEMT) technology have always been challenging because of the nonideal semiconductor–dielectric interface, which leads to electronic traps. Plasma‐enhanced chemical vapor deposition and atomic layer deposition are standard techniques, but they require surface treatment and post‐annealing to control these traps. This article explores metal organic chemical vapor deposition‐grown in situ aluminum nitride (AlN) as a gate dielectric. The interface is expected to be pristine as there is no change in the chamber environment. A thin (10 nm) AlN layer is deposited at a low temperature to minimize strain and prevent the formation of an unwanted conductive channel within the device. The electrical and structural properties of this AlN‐capped HEMT are compared to a standard GaN‐capped HEMT, including temperature‐dependent studies. The results show that the AlN‐capped HEMT retains a higher charge in the channel while having an order of magnitude lower gate leakage than the GaN‐capped sample. Furthermore, the AlN‐capped HEMT performs similarly to the GaN‐capped HEMT in terms of temperature‐dependent leakage, dynamic on‐resistance, and temperature coefficient of resistance. [ABSTRACT FROM AUTHOR]

Understanding the performance of polymer dielectrics at different temperatures is becoming increasingly important due to the rapid development of electric cars, electromagnetic devices, and new energy production solutions. Cyclic olefin copolymers (COCs) are an attractive material due to their low water absorption, good electrical insulation, long-term stability of surface treatments, and resistance to a wide range of acids and solvents. This work focused on the dielectric and electrical properties of cyclic olefin copolymer (COC)/Al2O3 composites over a wide range of temperature and frequency domains, from room temperature to cryogenic temperatures (around 125 K). Permittivity, electrical conductivity, and electrical modulus are given consideration. A composite of up to 50% Al2O3 mixed with COC was prepared via a conventional melt-blending method. The final samples were formed in sheets and processed using injection and extrusion moldings. It was found that formulations with Al2O3 concentrations ranging from 10 to 50% resulted in higher electrical conductivity while maintaining the viscosity of the composite at a level acceptable for polymer-processing machinery. Our data show that COC/alumina composites present substantial potential as materials for high-frequency applications, even at the regime of cryogenic temperatures. [ABSTRACT FROM AUTHOR]

Light dragging phenomena in accelerated media have classically been modelled neglecting the effect of inertia on the dielectric response of the media. Here, we show that the inertial corrections due to a rotating motion can have a profound impact on light-dragging manifestations, leading notably to birefringence in media that are isotropic at rest. By applying these findings to a rotating unmagnetized plasma, we further reveal how inertia plays, in this case, a dominant role, offering unique opportunities to expose these new effects. Inertia is notably demonstrated to be the source of non-zero drag and enhanced polarization drag, pointing to fundamental differences between linear and angular momentum coupling. In taking advantage of the singular properties of plasmas, this work more generally underlines how rest-frame properties are affected by an accelerated motion, and how these modifications can carry over to wave dynamics. [ABSTRACT FROM AUTHOR]