Elaboration and dielectric property of modified PZT/epoxy nanocomposites (original) (raw)
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Journal of Engineering Materials and Technology, 2011
Two-phase PZT-epoxy piezoelectric composites and three phase PZT-epoxy-Al composites were fabricated using a poling voltage of 0.2 kV/mm. The influence of aluminum inclusion size (nano and micron) and (lead zirconate titanate) PZT volume fraction on the dielectric properties of the three phase PZT-epoxy-aluminum composites were experimentally investigated. In general, dielectric and piezoelectric properties of the PZT-epoxy matrix were improved with the addition of aluminum particles. Composites that were comprised of ...
Journal of Electroceramics, 2009
PLZT-P(VDF/TFE) 0-3 composites with nanosized lead lanthanum zirconate titanate (Pb 0.92 La 0.08 )(Zr 0.65 Ti 0.35 )O 3 (PLZT 8/65/35) ceramic powders of volume fraction Φ up to 0.2 were fabricated using PLZT powders imbedded in a copolymer P(VDF/TFE)(0.98/0.02) matrix. The PLZT nanopowders were prepared by the sol-gel technique. The PLZT-P (VDF/TFE) composite samples were prepared from ceramic and polymer powders by the hot-pressing method. Dielectric response was studied in the frequency range from 100 Hz to 1 MHz and at temperatures from 100 to 450 K. The pyroelectric properties were studied by dynamic method with modulation frequency from 1 to 100 Hz. The dielectric response of the ceramics-polymer composite was found to be a combination of the responses of the pure polymer and the ceramics: (1) the addition of the PLZT ceramics increases the value of the dielectric permittivity ɛ′, (2) the composite shows the maximum of the permittivity coming from the PLZT ceramics, (3) the temperature dependences of the dielectric loss tgδ are characterized by the maximum attributed to the α-relaxation (glass transition) in the pure polymer. The pyroelectric coefficient of the composite increases from ∼20 μC/m 2 K in pure P(VDF/TFE) to ∼140 μC/m 2 K in the composites of Φ=0.15.
Dielectric properties of PZT–epoxy composite thick films
Journal of Alloys and Compounds, 2013
Composites with 0-3 connectivity patterns were prepared by gravity casting by using different amounts of Pb(Zr,Ti)O 3 powder with concentrations (x = 0%, 2.5%, 5%, 7.5%, 10% and 15%) embedded into a polymer matrix of epoxy resin. The role of the filling factor and of the gradient composition on the effective dielectric properties was theoretically investigated by Finite Element Method. The frequency dependencies of the real and imaginary parts of the dielectric permittivity at various temperatures showed a few relaxation mechanisms that were discussed. The composites exhibit a permittivity gradient and act as a natural impedance match system in the frequency range of 2-6 GHz, resulting in very low reflections. The compositionally graded PZT-epoxy resin composite thick films are suitable as adapting impedance materials for microwave applications.
Ceramics International, 2017
In this paper, we present a method to create a highly sensitive piezoelectric quasi 1-3 composite using a thermoplastic material filled with a piezoelectric powder. An up-scalable hightemperature dielectrophoresis (DEP) process is used to manufacture the quasi 1-3 piezoelectric polymer-ceramic composites. For this work, thermoplastic cyclic butylene terephthalate (CBT) is used as a polymer matrix and PZT (lead zirconium titanate) ceramic powder is chosen as the piezoelectric active filler material. At high temperatures, the polymer is melted to provide a liquid medium to align the piezoelectric particles using the DEP process inside the molten matrix. The resulting distribution of aligned particles is frozen upon cooling the composite down to room temperature in as little as 10 min. A maximum piezoelectric voltage sensitivity (g33) value of 54 ± 4 mV•m/N is reported for the composite with 10 vol% PZT, which is twice the value calculated for PZT based ceramics.
Two-phase PZT-epoxy piezoelectric composites and three phase PZT-epoxy-Al composites were fabricated using a poling voltage of 0.2 kV/mm. The influence of aluminum inclusion size (nano and micron) and (lead zirconate titanate) PZT volume fraction on the dielectric properties of the three phase PZT-epoxy-aluminum composites were experimentally investigated. In general, dielectric and piezoelectric properties of the PZT-epoxy matrix were improved with the addition of aluminum particles. Composites that were comprised of micron scale aluminum inclusions demonstrated higher piezoelectric d33-strain-coefficients, and higher dielectric loss compared to composites that were comprised of nanosize aluminum inclusions. Specifically, composites comprised of micron sized aluminum particles and PZT volume fractions of 20%, 30%, and 40% had dielectric constants equal to 405.7, 661.4, and 727.8 (pC/N), respectively, while composites comprised of nanosize aluminum particles with the same PZT volume fractions, had dielectric constants equal to 233.28, 568.81, and 657.41 (pC/N), respectively. The electromechanical properties of the composites are influenced by several factors: inclusion agglomeration, contact resistance between particles, and air voids. These composites may be useful for several applications: structural health monitoring, energy harvesting, and acoustic liners.
Dielectric Properties of Modified Lead Zirconate Titanate
Journal of Mountain Research, 2021
In this paper, the dielectric properties of modified i. e. alkali doped lead zirconate titanate Pb(Zr1- xTix)O3 has been studied. The composition Pb1-x (La1-zDz)x (Zry Ti1-y)1-x/4 O3;where x = 0.10, y = 0.70, z = 0.0, 0.1, 0.2, and 0.3, D= Na, K and Li has been prepared by conventional mixed oxide method at a temperature of 11000C. Dielectric constant and dielectric loss measurement of the sintered pellets has been measured. Dielectric measurement shows that the dielectric constant decreases with an increase in temperature. The results show that the dielectric loss is very small and decreases with frequency above 300°C. The increase in the dielectric constant observed at high temperatures and low frequencies is explained in the paraelectric state.
The influence of ZnO nanoparticles on the dielectric properties of epoxy resin
APPLIED PHYSICS OF CONDENSED MATTER (APCOM 2019)
Interesting electrical properties represent the epoxy nanocomposites, because the addition of nanofillers to a pure epoxy resin demonstrate several advantages opposite to pure epoxy resin without nanofillers. In the last 20 years, the dielectric properties (the complex permittivity and dissipation factor) of epoxy nanocomposites had been evaluated and the results clearly show that they are lower than that of base epoxy and microcomposites when insulating oxides were used as the fillers. Nowadays the epoxy and epoxy based composites are preferred insulating materials for many electrical applications. The influence of the various concentrations of ZnO nanoparticles in epoxy resin Vukol 022 on the changes of the complex permittivity and dissipation factor has been measured at the temperature range from 20 °C to 120 °C by a capacitance method in the frequency ranges from 1 mHz to 1 MHz. In this contribution, we present a study of the influence of 1,0 wt.% and 5,0 wt. % concentrations of ZnO nanofillers on the dielectric properties of the epoxy resin. From the frequency dependence of dissipation factor, α-relaxation process and its shift to lower frequencies with ZnO fillers were observed.
Fabrication and Electrical Properties of Lead Zirconate Titanate-Cement-Epoxy Composites
Ferroelectrics, 2010
Lead zirconate titanate (Pb (Zr 0:53 Ti 0:47 )O 3 , PZT) ferroelectric ®lms 2±60 mm in thickness have been successfully fabricated on Pt-coated oxidized Si substrates (Pt / Ti / SiO 2 / Si) by a new sol-gel-based process. The ®lms are a 0-3 ceramic±ceramic composite formed by dispersing ceramic powders in a sol-gel solution. The precursor solution for spin coating was prepared from lead acetate, tetrabutyl titanate, and zirconium nitrate. The microstructure and morphology of the prepared PZT thick ®lms were investigated via X-ray diffractometry (XRD) and scanning electron microscopy techniques. XRD analysis shows that the thick ®lms possess single-phase perovskite-type structure, no pyrochlore phase exists in thick ®lms, and SEM micrographs suggest that the PZT thick ®lms were uniform, dense, and crack free. A dielectric constant of 860, loss tangent of 0.03, remanent polarization of 25 mC cm À 2 , and a coercive ®eld of 40 kV cm À 1 were measured on 50 mm thick ®lms. Figure 6 P±E hysteresis loop of 50 mm PZT thick ®lms; P r 25 mC cm À 2 , E c 40 kV cm À 1 .
Energies
The paper presents the effects of gradual temperature curing on the dielectric properties of epoxy nanocomposite samples. Samples were prepared based on Class H epoxy resin filled with nano-alumina (Al2O3) for different wt% loadings (0.5 wt% to 5.0 wt%) and two different filler sizes (13 nm and <50 nm), i.e., two different specific surface area values. During the research, specimen sets were cured gradually at increasingly higher temperatures (from 60 °C to 180 °C). Broadband dielectric spectroscopy (BDS) was used to determine the characteristics of the dielectric constant and the dielectric loss factor in the frequency range from 10−3 Hz to 105 Hz. As a result, it was possible to analyze the impact of the progressing polymer structure thermosetting processes on the observed dielectric parameters of the samples. The nano-Al2O3 addition with 0.5 wt%, 1.0 wt%, and 3.0 wt% resulted in a decrease in dielectric constant values compared to neat epoxy resin samples. The most significant...