The electrical and dielectric properties of PVA/
Mg[ClO4]2 hybrid films were investigated in the temperature
range of 90–150 C and the frequency range of
20 Hz–10 MHz using impedance and modulus spectroscopy.
Impedance and modulus analyses had indicated
the temperature independent distribution of relaxation
times and the non-Debye behavior in these composites. The
co-operative motion due to strong coupling between the
mobile Mg2? ions is assumed to give rise to non-Debye
type of relaxation. Complex impedance Nyquist plots are
used to interpret the relaxation mechanism. The nature of
Nyquist plot confirms the presence of bulk effects, grain
boundaries and electrolyte/electrode polarization, and nonDebye
type of relaxation processes occurs in the composites.
A thermally activated relaxation was observed, which
was ascribed to be a non-Debye-type relaxation caused by
the mobility of magnesium ion in polymer matrix. A
comparison between Z00, imaginary part of complex impedance,
and M00, imaginary part of complex electric modulus,
indicates that the short- and long-range charge motion
dominates at low and high temperatures, respectively. The
activation energies, which were obtained from the electric
modulus and bulk conductivity, are matched well. The noncoincidence
of peaks corresponding to the modulus and
impedance indicates deviation from Debye-type relaxation. |
