Electrical conductivity and dielectric characteristics of in situ prepared PVA/HgS nanocomposite films

Polyvinyl alcohol (PVA) and mercury sulfide (HgS) polymer nanocomposite were prepared using the solution casting and the in situ chemical reduction of mercury nitrate (Hg(NO 3 ) 2 ) and sodium sulfide (Na 2 S) in aqueous solutions of PVA as capping for different molar content of Hg(NO 3 ) 2 and Na 2 S. The nanocomposites films were characterized by Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy. The XRD results for the nanoparticles revealed the hexagonal structure of the HgS, (α-phase). The influence of embedded HgS nanoparticles on the conductivity and dielectric properties of PVA films are investigated, over the frequency range 1 kHz–1 MHz, and the temperature range 30–110 °C. The variation of ac-conductivity with a frequency of the films follows Jonscher’s universal power law and found to be increased with increasing temperature, frequency and nanoparticle content. The variation of frequency exponent ( s ) indicated that the conduction mechanism was correlated barrier hopping model. The dielectric constant ( ɛ ′), and dielectric loss ( ɛ″ ) was found to decrease with increasing frequency, but increase with increasing temperature and HgS nanoparticles content. The dc-conductivity ( σ dc ) increase with increase of HgS concentration, and follows Arrhenius behavior in the investigated temperature region.