Electric and dielectric behavior of copper-chromium layered double hydroxide intercalated with dodecyl sulfate anions using impedance spectroscopy

• Published in: Solid state sciences Vol. 79; pp. 23 - 29
• Main Authors: Elhatimi, Wafaa, Bouragba, Fatima Zahra, Lahkale, Redouane, Sadik, Rachid, Lebbar, Nacira, Siniti, Mostapha, Sabbar, Elmouloudi
• Format: Journal Article
• Language: English
• Published: Elsevier Masson SAS 01-05-2018
• Subjects: Complex impedance spectroscopy; Dielectric constant; Electrical equivalent circuit; Ionic conductivity; Layered double hydroxide; Electrical equivalent circuit; Dielectric constant; Complex impedance spectroscopy; Layered double hydroxide; Ionic conductivity
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2018.03.006

The Cu2Cr-DS-LDH hybrid was successfully prepared by the anion exchange method at room temperature. The structure, the chemical composition and the physico-chemical properties of the sample were determined using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and inductively coupled plasma (ICP). In this work, the electrical and dielectric properties investigated are determined using impedance spectroscopy (IS) in a frequency range of 1 Hz to 1 MHz. Indeed, the Nyquist diagram modelized by an electrical equivalent circuit showed three contributions attributed respectively to the polarization of grains, grains boundaries and interface electrode-sample. This modelization allowed us to determine the intrinsic electrical parameters of the hybrid (resistance, pseudo-capacitance and relaxation time). The presence of the non-Debye relaxation phenomena was confirmed by the frequency analysis of impedance. Moreover, the evolution of the alternating current conductivity (σac) studied obeys the double power law of Jonscher. The ionic conduction of this material was generated through a jump movement by translation of the charge carriers. As for the dielectric behavior of the material, the evolution of dielectric constant as a function of frequency shows relatively high values in a frequency range between 10 Hz and 1 KHz. The low values of the loss tangent obtained in this frequency zone can valorize this LDH hybrid.
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•The Cu2Cr-DS-LDH hybrid was successfully prepared using the anion exchange method at room temperature.•Modelization of Cu2Cr-DS-LDH hybrid by three blocs electrical equivalent circuit.•The AC conductivity is found to obey the universal double power law.•The dielectric properties can valorize the LDH hybrid in the appropriate frequency zone.