Related Experiment Video
Updated: Aug 31, 2025
08:23
Finite Element Modelling of a Cellular Electric Microenvironment
Published on: May 18, 2021
3.5K
Frequency-Dependent Dielectric Permittivity in Poisson-Nernst-Planck Model.
M P Rosseto1, L R Evangelista1, E K Lenzi2
1Department of Physics, Maringá State University, Maringá, Paraná 87020-900, Brazil.
The Journal of Physical Chemistry. B
|August 19, 2022
Summary
This study integrates molecular polarization and ion dynamics in dielectric materials, revealing their interconnected effects on material properties across different frequencies. The findings clarify how charge densities influence permittivity and impedance.
Area of Science:
- Materials Science
- Physical Chemistry
- Dielectric Spectroscopy
Background:
- Traditionally, molecular polarization and ion dynamics in dielectrics are studied independently.
- These phenomena are often assumed to occur in distinct frequency ranges: ionic migration at low frequencies and molecular polarization at high frequencies.
Purpose of the Study:
- To investigate the interplay between free and bound charge densities.
- To understand their combined influence on permittivity and impedance profiles in dielectric materials.
- To incorporate frequency-dependent polarizability into the Poisson-Nernst-Planck model.
Main Methods:
- Development of a modified Poisson-Nernst-Planck (PNP) model.
- Inclusion of frequency-dependent (non-instantaneous) polarizability within the model.
- Analysis of dielectric material responses.
Main Results:
- Demonstration of the interplay between ionic and molecular charge dynamics.
- Quantification of their combined impact on dielectric permittivity.
- Characterization of their influence on impedance spectra.
Conclusions:
- The proposed PNP model effectively captures the coupled behavior of charge carriers.
- Frequency-dependent polarizability is crucial for accurately modeling dielectric responses.
- This unified approach enhances understanding of dielectric material behavior.
More Related Videos
Related Concept Videos
01:26Susceptibility, Permittivity and Dielectric Constant
1.8K
When placed in an external electric field, a dielectric material gets polarized. The charge density in the dielectric material is given by the sum of the bound and free charge densities, while the total charge density can also be written in terms of the total electric field. The bound charge density can be measured in terms of polarization, leading to the relationship between electric displacement and polarization.
1.8K
01:25Poisson's And Laplace's Equation
3.4K
The electric potential of the system can be calculated by relating it to the electric charge densities that give rise to the electric potential. The differential form of Gauss's law expresses the electric field's divergence in terms of the electric charge density.
3.4K
01:31Dielectric Polarization in a Capacitor
5.0K
The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
5.0K
01:27Electrostatic Boundary Conditions in Dielectrics
1.4K
When an electric field passes from one homogeneous medium to another, crossing the boundary between the two mediums imparts a discontinuity in the electric field. This results in electrostatic boundary conditions that depend on the type of mediums the field propagates through.
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's...
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's...
1.4K
01:30Electromagnetic Waves in Matter
3.3K
Electromagnetic waves can travel in the vacuum as well as in matter. For example light, which is an electromagnetic wave, can travel through air, water, or glass.
Consider the electromagnetic wave passing through a dielectric medium. In such a case, Maxwell's equations get modified. In Ampere's law, ε0 , the dielectric permittivity of free space is replaced with ε, the permittivity of dielectric. Also, the vacuum permeability μ0 is replaced by the permeability of the...
Consider the electromagnetic wave passing through a dielectric medium. In such a case, Maxwell's equations get modified. In Ampere's law, ε0 , the dielectric permittivity of free space is replaced with ε, the permittivity of dielectric. Also, the vacuum permeability μ0 is replaced by the permeability of the...
3.3K
01:17Gauss's Law in Dielectrics
4.6K
Consider a polar dielectric placed in an external field. In such a dielectric, opposite charges on adjacent dipoles neutralize each other, such that the net charge within the dielectric is zero. When a polar dielectric is inserted in between the capacitor plates, an electric field is generated due to the presence of net charges near the edge of the dielectric and the metal plates interface. Since the external electrical field merely aligns the dipoles, the dielectric as a whole is neutral. An...
4.6K