Electrical properties and conduction mechanism of the NaMg4(PO4)3 compound

The NaMg4(PO4)(3) phosphor was prepared by the conventional high-temperature solid-state reaction. The phase formation of the compound was confirmed by the powder X-ray diffraction. Electrical properties of the compound have been studied using complex impedance spectroscopy in the frequency range 209 Hz-1 MHz and temperature range 648-712 K. The AC conductivity for grain contribution was interpreted using the universal Jonscher's power law. The temperature dependence of frequency exponent s was investigated to understand the conduction mechanism in NaMg4(PO4)(3) compound. The non-overlapping small polaron tunneling model can explain the temperature dependence of the frequency exponent, and it was a closely good model to describe the dominant conduction mechanism.