Electrical conductivity and dielectric analysis of NaH2PO4 compound

Abstract

The sodium dihydrogen phosphate NaH2PO4 can be obtained by slow evaporation at room temperature and characterized by X-ray powder diffraction, scanning electron microscopy (SEM), and electrical impedance spectroscopy. The X-ray diffraction pattern revealed that the sample presents a single phase that crystallizes in the monoclinic structure with a P21/c space group, and the unit cell parameters are a = 6.8034 A, b = 13.4014 A, c = 7.2986 A, and β = 92.827°. The dielectric impedance properties were studied over the range of frequency between 103 Hz and 1 MHz and in the temperature range of 300–440 K. The Z′ and Z″ versus frequency plots are well fitted to an equivalent circuit model. The circuits consist of the parallel combination of resistance (R), fractal capacitance (CPE), and capacitance (C). Furthermore, the frequency-dependent AC conductivity obeys Jonscher’s universal power law. In fact, the near values of activation energy obtained from the modulus spectra and conductivity confirm that the transport happens through a proton-hopping mechanism, dominated by the motion of the proton H+ in the structure of the investigated materials.