Dielectric loss

About: Dielectric loss is a research topic. Over the lifetime, 20296 publications have been published within this topic receiving 349254 citations.

Li+ ion conduction mechanism in poly (ε-caprolactone)-based polymer electrolyte

Abstract: In this work, solid polymer electrolytes based on poly(ɛ-caprolactone) (PCL) with lithium bis(oxalato)borate as a doping salt were prepared by solution cast technique using DMF as a solvent. The electrical DC conductivity and dielectric constant of the solid polymer electrolyte samples were investigated by electrochemical impedance spectroscopy over a frequency range from 50 Hz to 1 MHz. It was found that the DC conductivity increased with increase in the salt concentration to up to 4 wt% and thereafter decreased. Dielectric constant versus salt concentration was used to interpret the decrease in DC conductivity with increase in salt concentration. The DC conductivity as a function of temperature follows Arrhenius behavior in low temperature region, which reveals that ion conduction occurs through successful hopping. The curvature of DC conductivity at high temperatures indicates the contribution of segmental motion to ion conduction. High values for dielectric constant and dielectric loss were observed at low frequencies. The plateau of dielectric constant and dielectric loss at high frequencies can be observed as a result of rapid oscillation of the AC electric field. The HN dielectric function was utilized to study the dielectric relaxation. The experimental and theoretical data of dielectric constant are very close to each other at low temperatures. At high temperatures, the simulated data are more deviated from the experimental curve of dielectric constant due to the dominance of electrode polarization. The non-unity of relaxation parameters (α and β) reveals that the relaxation processes in PCL-based solid electrolyte is a non-Debye type of relaxation.

Enhanced Energy Storage and Suppressed Dielectric Loss in Oxide Core–Shell–Polyolefin Nanocomposites by Moderating Internal Surface Area and Increasing Shell Thickness

Abstract: Dielectric loss in metal oxide core/Al(2)O(3) shell polypropylene nanocomposites scales with the particle surface area. By moderating the interfacial surface area between the phases and using increasing shell thicknesses, dielectric loss is significantly reduced, and thus the energy stored within, and recoverable from, capacitors fabricated from these materials is significantly increased, to as high as 2.05 J/cm(3).

Dielectric enhancement in polymer-nanoparticle composites through interphase polarizability

Abstract: Dielectric measurements on polyimide-oxide nanoparticle composite thin films show a composite dielectric constant (ecomposite) that increased monotonically with increasing oxide content well above the value predicted by Maxwell’s rule for dielectric mixtures below the percolation threshold. Above certain volume fractions, the measured ecomposite values were found to exceed the corresponding nanoparticle e such that epolymer

Piezoelectric Al1−xScxN thin films: A semiconductor compatible solution for mechanical energy harvesting and sensors

Abstract: The transverse piezoelectric coefficient e31,f of Al1-xScxN thin films was investigated as a function of composition. It increased nearly 50% from x = 0 to x = 0.17. As the increase of the dielectric constant was only moderate, these films are very suitable for energy harvesting, giving a 60% higher transformation yield (x = 0.17) as compared to pure AlN. A higher doping might even lead to a 100% augmentation. The thickness strain response (d33,f) was found to increase proportionally to the ionic part of the dielectric constant. The e-type coefficients (stress response), however, did not augment so much as the structure becomes softer. As a result, the transverse voltage/strain response (h31,f-coefficient) was raised only slightly with Sc doping. The low dielectric loss obtained at all compositions suggests also the use of Al1−xScxN thin films in sensors.

Microstrip Propagation on Magnetic Substrates - Part I: Design Theory

Abstract: Formulas and graphs are presented for the effective relative permeability and the filling factors of magnetic substrates in microstrip. Both the propagation and the magnetic loss filling factors are included. In the calculation of these quantities, use was made of the filling factors for dielectric substrates obtained from Wheeler's analysis and a duality relationship between magnetic and dielectric substrates derived in this paper.