Impedance spectroscopy and conduction mechanism of NaYP 2 O 7 ceramic compound

In the present study, NaYP2O7 compound was prepared by solid-state method and was characterized by powder X-ray diffraction and Raman spectroscopy. The X-ray diffraction of the sample at room temperature showed a monoclinic phase. Electrical conductivity and modulus studies over a wide range of frequencies (40 Hz to 7 MHz) and temperature (400–560 K) were studied using impedance spectroscopic technique. The impedance plane plot shows semicircle arcs at different temperatures and an electrical equivalent circuit has been proposed to explain the impedance results. The ac conductivity of the investigated compound obeys the power law: σac(ω) = σdc + Aωn where n < 1. The frequency-dependent maxima of the imaginary part of modulus are found to obey Arrhenius law with activation energy 0.64 eV. The activation energy responsible for dielectric relaxation extracted from the modulus spectra is found to be almost the same as the value obtained from the equivalent circuit. These results indicate that the transport is through ion hopping mechanism dominated by the motion of the Na+ ion in the structure of the investigated material.