Activation energy of polarization due to electrical conductivity and dipole rotation in purified ca-bentonite
Küçük Resim Yok
Tarih
2012
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
ELSEVIER
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
We determined the activation energy for dipole rotation and electrical conductivity by analyzing the frequency dependent dielectric permittivity measurements of purified Ca-Bentonite. The measurements were performed at four different temperatures between 296 K and 353 K and at frequencies between 5 Hz to 5 MHz. We used the Havriliak-Negami (HN) relation to represent the polarization due to dipole orientations and the Maxwell-Wagner-Sillars (MWS) relation with a power law term to represent the interfacial polarization. We obtained expressions for the real and imaginary parts of electric modulus M*(omega). We determined the relaxation times for HN and MWS contributions from a fit of the experimental data. Subsequently, the activation energies for HN and MWS contributions were obtained from an Arrhenius plot. The activation energy for the HN and MWS processes were found to be 22.3 kJ/mot and 18.2 kJ/mol, respectively. (C) 2012 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Ca-bentonite, Dielectric relaxation, Orientational polarization, Interfacial polarization, Electric modulus, Activation energy
Kaynak
APPLIED CLAY SCIENCE
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
62-63
