AC and DC conductivity study of KPb4(PO4)3 compound using impedance spectroscopy

Orthophosphate KPb4(PO4)3 compound was synthesized by the conventional solid-state reaction. The phase formation of the compound was confirmed from the powder X-ray diffraction. Vibrational study confirms the existence of [PO4]3− group. The impedance spectroscopy measurements was realized with Compact disc, Φ = 8 mm diameter and 1.2 mm thickness in the range temperature (659-708)K and frequency (209 Hz-1 MHz), respectively. As well, the impedance spectra are well adjusted to an equivalent circuit formed by a serial combination of three cells. It was found that the non-overlapping small polaron tunneling (NSPT) model is suitable to describe the conduction mechanism in this compound.