LAUSR

Abstract The main objective of this work is to investigate the electrical and dielectric properties of copper divanadates α-Cu2V2O7 and β-Cu2V2O7 using impedance spectroscopy. The samples were prepared by the solid state. The desired phases were obtained and confirmed by the X-ray powder diffraction, α-Cu2V2O7 is orthorhombic and β-Cu2V2O7 is monoclinic. The analysis of electrical and dielectric properties was investigated in the frequency range [0.1 Hz-1MHz] at room temperature. The Cole-Cole diagrams show two non-Debye relaxations attributed to the polarization of grains and grain boundaries. The modelization and the deconvolution of impedance spectra using an equivalent circuit consisting of two R-CPE blocs connected in series confirm the observed relaxations. The conductivity (σT) depends on the frequency and follows the double power law. Also, this study explains that the α-Cu2V2O7 phase in which the sites containing the Cu2+ ions carrying charges are regular, is more conductive compared to β-Cu2V2O7. We note that the two phases studied have interesting dielectric properties which concern the higher values of the dielectric loss tangent obtained in the frequency lower than 1 KHz. Hence, it is suitable to use these materials as electric attenuation absorbers.