Dielectric Properties Case Study
3.7. Dielectric Studies
Dielectric properties are the complex function of bulk permittivity, conductivity, size, shape, frequency and spatial arrangement of the constituents [27]. The Dielectric complex permittivity is written as where, the real part εr and imaginary part ε″ are known as dielectric constant and dielectric loss accounts for the energy storage and energy loss respectively. The dielectric constant is calculated with the relation εr=Cd/εoA where, C is series capacitance value, d is the thickness of the sample, A is the area of the electrode and εo(= 8.85×10−12 F m-1) is permittivity of free space and ε″ is the dielectric loss (ε”= εr tan δ). The ac conductivities at different frequencies for the polymer composites …show more content…
After 10 wt.% Bi(NO3)3 concentration, it will act as an insulating filler by the formation of aggregates. The ac conductivity of the samples increase with increase in frequency attributed to the hopping of polarons between the sites within the polymer matrix. The increasing ac conductivity behavior is connected to the electrode-electrolyte phenomena which results from electrode polarization effects. The obtained values of dielectric constant and ac conductivity for 10% Bi(NO3)3 doped PVA-LiClO4 composite is higher than that of undoped PVA-LiClO4 sample. The dielectric constant and ac conductivity of the 10% Bi(NO3)3 doped PVA-LiClO4 composite are 11.8 and 2.98 10-4 S cm-1 at 10 kHz, which are much higher compare to some PVA based polymer electrolytes like MnCl2 doped PVA/PEO system and Alumina doped PVA [32, 33].
3.7.2. Variation of dielectric properties with temperature
The temperature dependence of the dielectric constant, dielectric loss and ac conductivity is studied for 10% Bi(NO3)3 doped PVA-LiClO4 as it exhibits the highest dielectric parameters and ac conductivity and the variations are shown in Fig.
Dielectric properties are the complex function of bulk permittivity, conductivity, size, shape, frequency and spatial arrangement of the constituents [27]. The Dielectric complex permittivity is written as where, the real part εr and imaginary part ε″ are known as dielectric constant and dielectric loss accounts for the energy storage and energy loss respectively. The dielectric constant is calculated with the relation εr=Cd/εoA where, C is series capacitance value, d is the thickness of the sample, A is the area of the electrode and εo(= 8.85×10−12 F m-1) is permittivity of free space and ε″ is the dielectric loss (ε”= εr tan δ). The ac conductivities at different frequencies for the polymer composites …show more content…
After 10 wt.% Bi(NO3)3 concentration, it will act as an insulating filler by the formation of aggregates. The ac conductivity of the samples increase with increase in frequency attributed to the hopping of polarons between the sites within the polymer matrix. The increasing ac conductivity behavior is connected to the electrode-electrolyte phenomena which results from electrode polarization effects. The obtained values of dielectric constant and ac conductivity for 10% Bi(NO3)3 doped PVA-LiClO4 composite is higher than that of undoped PVA-LiClO4 sample. The dielectric constant and ac conductivity of the 10% Bi(NO3)3 doped PVA-LiClO4 composite are 11.8 and 2.98 10-4 S cm-1 at 10 kHz, which are much higher compare to some PVA based polymer electrolytes like MnCl2 doped PVA/PEO system and Alumina doped PVA [32, 33].
3.7.2. Variation of dielectric properties with temperature
The temperature dependence of the dielectric constant, dielectric loss and ac conductivity is studied for 10% Bi(NO3)3 doped PVA-LiClO4 as it exhibits the highest dielectric parameters and ac conductivity and the variations are shown in Fig.