Relaxation and conduction mechanism of PVA: BYZT polymer composites by impedance spectroscopy

Abstract

Frequency dependent dielectric, modulus, impedance and AC conductivity study of Poly Vinyl Alcohol with 25 vol.% of Yttrium modified Barium Zirconium Titanate ceramic have been investigated. The single phase Yttrium modified Barium Zirconium Titanate ceramics have been synthesized by conventional solid state route. The relaxation mechanism of dielectric and modulus study is due to the segmental motion of polymer chain along with the dipole orientation of ceramic in the polymer composite. The Nyquist plot of impedance shows two semicircles, which represents the bulk and interfacial effect of polymer composites. The activation energy decreases with incorporation of higher Yttrium modified Barium Zirconium Titanate ceramics in the polymer matrix due to the even distribution of ceramic in the polymer composite. The different activation energy obtained from conduction and relaxation of the composite indicates that various mechanisms are involved in the conduction and relaxation process.

Dielectric relaxation behavior and electrical conduction mechanism in polymer-ceramic composites based on Sr modified Barium Zirconium Titanate ceramic

“…The subsequent decrease in the activation energy of Sr modified BZT ceramic in PVA is supposed to be easy movement of charge carriers due to the even distribution of ceramics in the polymer matrix (supports SEM report) which makes the chains more soften and increases the segmental motion [3,19,20].…”

“…Decrement of activation energies in conductivity agrees with the decrement of relaxation activation energies by changing the composition with modified ceramic. However, the activation energy decreases with increasing the Sr modification in polymer composite explains the segmental motion easier which increases the diffusion of charges [3,20,28]. The activation energies of the relaxation process are higher than the conduction mechanism, which suggest that the relaxation process does not govern the conduction mechanism.…”

Synthesis, characterization, dielectric and rectification properties of PANI/Nd2O3:Al2O3nanocomposites

“…The electrical transport measurements were performed on fabricated structures by measuring the current-voltage (I-V) characteristics between top and bottom electrodes. [15] RESULTS AND DISCUSSION Fourier transform infrared spectroscopy [17]…”

The tunable permittivity of multi-walled carbon nanotubes/silver nanoparticles reinforced polyvinyl alcohol (PVA) nanocomposites at low frequency

“…The dielectric loss is due to the energy loss associated with charges motion and dipoles alignment. When the induced charges are unable to follow the periodic reversal of electric field, which is extremely fast at high frequency and could trigger to the decrease in ε″ values with a decline of the charges accumulation [31]. The features display large dielectric loss of the nanocomposites with increasing AgNP content up to 1.0 wt%, which is inversely proportional to the frequency and gradually decreased towards a higher frequency.…”

“…The charge carriers travelling over long distances at low frequency and upon reaching the maximum M″, their mobility is executed to localized motion over short distances. The peaks of M″ defines relaxation time, τ of the orientated dipoles (τ=1/ω p ), where the angular frequency is given by ω p =2πf [31]. It can be seen that the relaxation frequency of the nanocomposites shifted towards higher frequency and the relaxation time also reduced with the increased of AgNP.…”