LAUSR

Abstract The LiGd(WO 4 ) 2 compound is prepared using a solid-state reaction method. The X-ray diffraction studied and found to be a tetragonal system and I 4 1 / a space group. Vibrational study confirms the existence of (WO 4 ) 2− group. The electrical properties of this compound have been measured in the temperature range from 584 to 689 K and the frequency range from 209 Hz to 5 MHz. Nyquist plots reveals the presence of tow contributions, an equivalent circuit of combination of grains and grain boundary elements was proposed to modilize these plots. The spectra follow the Arrhenius law with two activation energy the first in the region of temperatures before 621 K (Region I) and the second in the region after 621 K (Region II). The Tauc model was used to determine the optical gap energy of the synthesized LiGd(WO 4 ) 2 compound. The absorption spectra indicate that the compound has a direct band gap (3.607 eV) due to the direct transition.