AC and DC conductivity study of ceramic compound NaGd(WO4)2 using impedance spectroscopy

In this works, the NaGd(WO 4 ) 2 compound was obtained by the conventional solid-state reaction method at 923 K, has been investigated by X-ray diffraction, vibrational and impedance spectroscopy. The X-ray diffraction’s results indicate that the sample possess single crystalline phase in the tetragonal system with space group I4 1 /a. The unit cell parameters are: a = 5.246(6) Å, c = 11.380(1) Å, and V = 313.257(8) Å 3 . Thus, the impedance spectroscopy measurements were performed in the (209Hz–5 MHz) frequency and the (613–711 K) temperature ranges. Besides, the ac conductivity contribution is interpreted using the universal Jonscher’s power law and is thermally activated with an activation energy of grain, grain boundary and total were 0.91(4), 0.79(3) and 0.97(5) eV respectively. The mechanism of conduction is due to the displacement of Na + ion that can be interpreted by the model NSPT (non-overlapping small polaron tunneling).