Spectroscopy Letters ( IF 1.7 ) Pub Date : 2021-02-25 , DOI: 10.1080/00387010.2021.1884576 M. Abdessamad 1 , M. Kharroubi 1 , A. Belbel 1
Abstract
The dielectric properties of a series of montmorillonite clays, namely, Li+, Na+, K+, Rb+ and Cs+-montmorillonite in dry state have been measured by means of complex impedance spectroscopy. These measurements are performed between 173 K and 473 K at frequencies ranging from 10−2 to 106 Hz. The objective of this study was to correlate the dielectric properties with the temperature and the nature of exchanged cations. The real and imaginary parts of the complex dielectric permittivity for the alkali-exchanged montmorillonites, show at fixed temperatures a decrease with increasing frequency, and on the other hand show an increase with increasing temperature. Furthermore, by considering the activation energy of cations, at a fixed temperature, the frequency dependence of the real and imaginary parts seemed to follow the polarizing power of the cations. The frequency dependence reveals significant dielectric losses in the low frequency range where the appearance of resonance peaks in the loss tangent is due to dielectric relaxation processes of this material.