1.Condensed Matter Laboratory, Faculty of Sciences,University of Sfax,Sfax,Tunisia;2.Laboratory of Physics of Materials and Nanomaterials applied to the Environment, Faculty of Sciences of Gabès,University of Gabès,Gabes,Tunisia
Abstract:
The optical properties of diphosphate LiCrP2O7 compound prepared by the classic ceramic method were recorded at room temperature. Absorption spectrum shows the presence of five characteristics bands related to the octahedral transitions of Cr3+ from ground term 4A2g to excited terms. Crystal field strength and inter electronic repulsion Racah parameters were deduced. The calculated value of direct ( {E}_g^{mathrm{direct}} )=1.62 eV energy gap has been found using Tauc’s procedure. Besides, the dielectric properties were carried out by impedance spectroscopy at different temperatures (460–700 K). The frequency and temperature dependent of the real ε′ and imaginary ε″ parts of the dielectric constant were discussed. The variation of the frequency power law of the imaginary part of dielectric constant was analyzed in terms of two different conduction mechanisms. Furthermore, the modulus plots can be characterized by the empirical Kohlrausch–Williams–Watts (K.W.W.) function and the obtained values of activation energies deduced from relaxation frequency are in order of Ea (I) = 0.49 eV and Ea (II) = 0.87 eV.
