Electrical and dielectric properties of the Li 1.5Na0.5WO4 compound

In the context to determinate the electrical proprieties of new composition of Li1.5Na0.5WO4 compound we have synthesized and characterized this compound by X-ray diffraction, Raman spectroscopy, calorimetric study and impedance spectroscopy. The purity of this compound is showed by the X-ray diffraction which indicates that this material has a monoclinic structure with P2/m space group and the lattice parameters are: a = 15.914 Å, b = 7.191 Å, c = 12.628 Å and β = 114.313°. All modes of vibrations of WO42− tetrahedral appear in the Raman spectrum. The calorimetric and dielectric studies show a single phase transitions at 501 K. The impedance spectroscopy shows the contribution of the grain which allows choosing an equivalent circuit modeled by parallel combination of resistance (R), a capacitance (C) and constant phase element (CPE). The variation of the σg and σdc as a function of temperature confirms the phase transition observed in the calorimetric study. The conduction mechanism in the two phases indicates that the first phase (I) described by the OLPT model and the second by the CBH model.