| Popis: |
Dielectric response and ac conductivity analysis of an ionically conducting polymer film based on polymethyl methacrylate (PMMA) as the host polymer have been carried out. The effect of frequency and salt concentration on the dielectric relaxation and on the ac conductivity has been observed. The dielectric behavior was analyzed via the dielectric permittivity (epsilon') and dissipation factor (tan delta) of the samples. The analysis has shown the presence space charge polarization at lower frequencies. Evidences of dielectric and conductive relaxation phenomena have also been traced. The dielectric peak has been observed to shift toward the higher frequency side with the addition of LiClO4 salt, suggesting a lowering the sample viscosity and the barrier to ion mobility. The real part of ac conductivity spectra of these materials obeys the Jonscher power law, where the calculated value of the power law exponent n lies between 0.5 and 1, which confirms that the electrical conductivity in the polymer nanocomposite electrolytes (PNCs) is primarily due to ionic transport. The hopping rate, carrier concentration term, has been determined using Almond-West formalism. A good correlation among dielectric permittivity, carrier concentration and ionic conductivity has been observed. |
