| Autor: |
SONI, VINOD KUMAR, MANMEETA, SAXENA, DHIRAJ |
| Předmět: |
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| Zdroj: |
i-Manager's Journal on Material Science; Apr-Jun2018, Vol. 6 Issue 1, p8-19, 12p |
| Abstrakt: |
Composites comprising of an active phase of ferroelectric ceramic and a polymer matrix have recently found numerous sensory and energy storage applications. However, it remains a major challenge to further improve their dielectric and electromechanical response at low loading of ceramics without losing their flexibility. The objective of this research work is to prepare three-phase flexible composites by incorporation of ZnO nanoparticles with various weight fractions into ceramic--polymer matrix, and analyzing the effect of these nano-fillers for optimizing piezoelectric and dielectric properties for various applications. This research aims at employing ZnO nanoparticles to develop highly sensitive piezoelectric composites for vibration / pressure sensing applications and electric energy storage devices by virtue of their significant dielectric and piezoelectric properties. Three phase composites consisting of Polyvinylbutyral (PVB) as host polymer matrix, ceramic Lead Zirconate Titanate (PZT) as active piezoelectric phase, and ZnO nanoparticles as third phase with vol% ranging from 1% to 12% were prepared using hot-press technique. The structural analysis of three phase composites PVB/PZT/ZnO were carried out by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). Addition of ZnO nanoparticles forms a percolative network in the composites resulting in enhancement of the electrical conductivity. The percolation threshold was obtained at 6 vol% of ZnO nanoparticles. A significant increase in the piezoelectric properties (d33 from 25 pC/N to 180 pC/N) of the composites was obtained just near the percolation threshold. ZnO nanoparticles contribute to piezoelectric coefficient by virtue of its noncentro symmetric structure and also by facilitating effective DC poling due to the creation of percolative continuity near percolation threshold. Variation of AC conductivity with frequency and temperature near percolation threshold suggests that hopping and tunneling are the dominating conduction mechanisms in these three phase composites. Experimental results were explained in the percolation transition region using percolation theory and models. These composites are flexible and can be fabricated into various shapes. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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