Cart (Loading....) | Create Account
Close category search window
 

Finite-element modeling method for the study of dielectric relaxation at high frequencies of heterostructures made of multilayered particle

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $31
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Fourn, Cedric ; Laboratoire d''Electronique et Systèmes de Télécommunications (Unité Mixte de Recherche CNRS 6165), Université de Bretagne Occidentale, CS 93837, 6 avenue Le Gorgeu, 29238 Brest Cedex 3, France ; Lasquellec, Sophie ; Brosseau, Christian

Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.2826686 

There has been much recent interest in how morphological descriptors may affect the electromagnetic wave transport in particulate composite mediums. In this work, we present results of finite-element simulations that model the permittivity of two-dimensional (or cross sections of infinite three-dimensional parallel, infinitely long, identical, circular cylinders, where the properties and characteristics are invariant along the perpendicular cross-sectional plane) three-phase heterostructures made of a multilayered discoidal particle. While strictly valid only in a direct current situation, our analysis can be extended to treat electric fields that oscillate with time provided that the wavelengths and attenuation lengths associated with the fields are much larger than the microstructure dimension in order that the homogeneous (effective medium) representation of the composite structure makes sense. From simulations over a range of parameters, our analysis evaluates the effect of the surface fraction of inclusion, the conductivity, and thickness (relative to the particle radius) of the particle conductive coating on the effective complex permittivity of isotropic heterostructures in which the filler particles have a core-shell structure. Four main effects are found. First, the importance of the surface fraction of inclusion on the effective complex permittivity at high frequencies (from microwave to infrared) is illustrated over a broad range of coating thicknesses and conductivities. Second, the encapsulation phase (metallic coating) conductivity is identified as the key property controlling the dielectric relaxation due to interfacial polarization. Third, a simple parametrization of the high-frequency effective permittivity spectrum allowed us to obtain a reliable modelization of the Debye-type relaxation processes. From the least-squares fit of the effective complex permittivity data, we extract information on these relaxation processes, i.e., relaxation frequencie- s, relaxation strengths, and the limiting high-frequency permittivity. A salient point is that for core-shell structures there is a transition between a single peak and a two-peak relaxation spectrum which is under the dependence of the coating thickness. Fourth, we show how the features of permittivity spectra depend on the local dielectric environment (matrix and inclusion core) and shell conductivity. These results may have experimental consequences in the recent experiments on the dielectric relaxation in nanocoated particles.

Published in:

Journal of Applied Physics  (Volume:102 ,  Issue: 12 )

Date of Publication:

Dec 2007

Need Help?


IEEE Advancing Technology for Humanity About IEEE Xplore | Contact | Help | Terms of Use | Nondiscrimination Policy | Site Map | Privacy & Opting Out of Cookies

A not-for-profit organization, IEEE is the world's largest professional association for the advancement of technology.
© Copyright 2014 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.