A New Method of Analysing Dielectric Measurements

Scaife, B. K. P.

doi:10.1088/0370-1328/81/1/318

Cited by 48 publications

(17 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the shifts for the modulus–compliance and for the losses–loss tangent transformations are in opposite directions to each other and, thus, tend to compensate, it seemed reasonable at this stage not to perform the transformations and, thus, to compare dielectric ϵ ″ and shear modulus tan δ peak frequencies with each other, bearing in mind the previously discussed points. It is interesting to mention here that Havriliak Jr. and Havriliak32 extended a recommendation made by Scaife33 for the comparison of dielectric data as complex polarizability rather than complex permittivity to the comparison of dielectric and viscoelastic data. The second point to be taken into account, valid for all the techniques, refers to the need to ensure a high reproducibility of the temperature measurements, a truly comparable temperature scale, and measurements on identical samples (e.g., water content) 8, 10…”

Section: Discussionmentioning

confidence: 74%

Phase behavior and molecular mobility in polyurethane/styrene–acrylonitrile blends

Vatalis¹,

Kanapitsas²,

Delides³

et al. 2001

J of Applied Polymer Sci

View full text Add to dashboard Cite

Differential scanning calorimetry (DSC), thermally stimulated depolarization currents (TSDC) techniques, dielectric relaxation spectroscopy (DRS), and dynamic mechanical thermal analysis (DMTA), covering together a wide range of temperatures and frequencies, were employed to investigate molecular mobility and microphase separation in blends of crosslinked polyurethane (PUR) and styrene-acrylonitrile (SAN) copolymer, prepared by reactive blending with polymer polyols. The results by each technique indicate that the degree of microphase separation of PUR into hardsegment (HS) microdomains and soft-segment (SS) microphase increases on addition of SAN. The various techniques were critically compared to each other, with respect to their characteristic time and length scales, on the basis of activation diagrams (Arrhenius plots). The results show that for the dynamic glass transition of the PUR SS microphase the characteristic time scales at the same temperature are similar for DMTA, DSC, and TSDC and shorter for DRS. In terms of fragility, the PUR/SAN blends are classified as fragile systems.

show abstract

Section: Discussionmentioning

confidence: 74%

Phase behavior and molecular mobility in polyurethane/styrene–acrylonitrile blends

Vatalis¹,

Kanapitsas²,

Delides³

et al. 2001

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Complex Polarizability. The dielectric response has further been analyzed using a new method, proposed by Scaife, 42 known as complex polarizability (α*). The parameter α* is especially advantageous in investigating the intrinsic dielectric properties of a material as it provides a proper weightage to all polarization mechanisms.…”

Section: Iiiiii DC Conductivitymentioning

confidence: 99%

Mechanism of Na-Ion Conduction in the Highly Efficient Layered Battery Material Na₂Mn₃O₇

Saha

Bera

Yusuf

2021

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

The ionic conduction properties of the technologically important two-dimensional (2D) layered battery material Na2Mn3O7, with exceptional small-voltage hysteresis between charge and discharge curves, have been investigated as a function of temperature and frequency by an impedance spectroscopy. The detailed analyses of the impedance data in the form of dc-conductivity, acconductivity, electrical modulus, dielectric constant and complex polarizability reveal a long-range Na-ionic conductivity with negligible contribution from a local dipole relaxation. A significant enhancement (~10 4 times) of the Na-ion conductivity has been found with the increasing temperature from 353 K to 713 K. The temperature dependent conductivity reveals thermally activated conduction process with activation energies of 0.161 and 0.377 eV over the two temperature regions of 383-518 K and 518-713 K, respectively. AC conductivity study reveals a long-range hopping process for the conduction of charge carriers with a sharp increase of the hopping range at 518 K. With the increasing frequency, the activation energies decrease for both the temperature regions. The scaling study of the ac-conductivity reveals that the frequency-activated conductivity (above νC =10 4 Hz at 353 K) is mainly controlled by the critical frequency (νC) that increases with the increasing temperature. Our results reveal that the thermally activated Na-ion conduction in the present 2D layered compound Na2Mn3O7 occurs predominantly by a correlated barrier hopping process. Besides, a correlation between ionic conduction and crystal structure has been established by x-ray and neutron diffraction study. We have further shown that the conductivity of Na2Mn3O7 can be enhanced by reduction of the stacking faults in the crystal structure. The present comprehensive study facilitates the understanding of the microscopic ionic conduction mechanism in the highly efficient 2D layered battery material Na2Mn3O7 having high energy storage capacity and high structural stability, paving way for the discovery of 2D materials for functional battery applications.

show abstract

“…Complex polarizability. To understand the phenomena of dielectric relaxation better, the complex polarizability a*, proposed by Scaife 20 was focused on next. This allows more investigation of the intrinsic dielectric properties of a compound because it gives appropriate weight to all polarization mechanisms.…”

Section: Optical Propertiesmentioning

confidence: 99%

Structural, optical, electric and dielectric characterization of a NaCu_0.2Fe_0.3Mn_0.5O₂ compound

et al. 2022

View full text Add to dashboard Cite

show abstract

A New Method of Analysing Dielectric Measurements

Cited by 48 publications

References 3 publications

Phase behavior and molecular mobility in polyurethane/styrene–acrylonitrile blends

Phase behavior and molecular mobility in polyurethane/styrene–acrylonitrile blends

Mechanism of Na-Ion Conduction in the Highly Efficient Layered Battery Material Na₂Mn₃O₇

Structural, optical, electric and dielectric characterization of a NaCu_0.2Fe_0.3Mn_0.5O₂ compound

Contact Info

Product

Resources

About

A New Method of Analysing Dielectric Measurements

Cited by 48 publications

References 3 publications

Phase behavior and molecular mobility in polyurethane/styrene–acrylonitrile blends

Phase behavior and molecular mobility in polyurethane/styrene–acrylonitrile blends

Mechanism of Na-Ion Conduction in the Highly Efficient Layered Battery Material Na2Mn3O7

Structural, optical, electric and dielectric characterization of a NaCu0.2Fe0.3Mn0.5O2 compound

Contact Info

Product

Resources

About

Mechanism of Na-Ion Conduction in the Highly Efficient Layered Battery Material Na₂Mn₃O₇

Structural, optical, electric and dielectric characterization of a NaCu_0.2Fe_0.3Mn_0.5O₂ compound