Dielectric constant of particles determined by impedance spectroscopy

Petrovsky, Vladimir; Manohar, Abhishek; Doğan, Fatih

doi:10.1063/1.2206411

Cited by 37 publications

(55 citation statements)

References 5 publications

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“…18 In the case of ferroelectric ceramics and polycrystalline films, the equivalent circuit includes several such parallel R-C connections associated with the electrode interfaces, grain boundaries, or grain bulk. [34][35][36] Eventually, a constant phase element is included to explain the deviation from the classical Debye behavior in the Cole-Cole plots. 37,38 The circuit can be simplified in the case of the epitaxial ferroelectric layers, by eliminating the elements related to the grain boundaries.…”

Section: Introductionmentioning

confidence: 99%

General equivalent circuit derived from capacitance and impedance measurements performed on epitaxial ferroelectric thin films

Pintilie

Hrib

Pasuk

et al. 2014

Journal of Applied Physics

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Voltage and frequency dependent capacitance measurements were performed on epitaxial BaTiO3 and Pb(Zr0.2Ti0.8)O3 thin films deposited on single crystal SrTiO3 substrates with (001) and (111) orientations. The measured capacitors have common bottom SrRuO3 contact and different metals as top electrodes: SrRuO3, Pt, Cu, Al, and Au. The capacitance-voltage characteristics were used to extract information regarding the density of the free carriers and the linear contribution to the static dielectric constant. The frequency dependent impedance was used to develop a suitable equivalent circuit for the epitaxial ferroelectric capacitors. It was found that the frequency dependence of the imaginary part of the impedance can be well simulated, in all cases, using a circuit composed of Schottky-type capacitance related to electrode interfaces, contact resistance, and the R-C parallel connection related to the ferroelectric volume of the film. Values for the components of the equivalent circuit were obtained by fitting the experimental data with the simulated curves. These were then used to extract quantities such as dielectric constant in the ferroelectric volume, the width of the depletion layers, and the apparent built-in potential. It was found that, although the investigated capacitors are of different ferroelectric materials, grown on substrates with different orientations, and having different metals as top electrodes, the values for the capacitance associated with the Schottky contacts and the apparent built-in potential are not very different. The results suggest a strong influence of ferroelectric polarization on the electrode interface properties in the case of epitaxial ferroelectric films.

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Section: Introductionmentioning

confidence: 99%

General equivalent circuit derived from capacitance and impedance measurements performed on epitaxial ferroelectric thin films

Pintilie

Hrib

Pasuk

et al. 2014

Journal of Applied Physics

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“…[19] The dielectric permittivity of the nanoparticles was determined by impedance spectroscopy using an appropriate equivalent circuit model. [20] P(VDF-TrFE-CTFE) with a composition of 78.8:5.4:15.8 mol% was synthesized via a copolymerization of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) and a subsequent dechlorination reaction. [21,22] The chemical composition of the polymer was calculated according to the integrals of the characteristic peaks in 1 H and [19] F NMR spectra.…”

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confidence: 99%

Nanocomposites of Ferroelectric Polymers with TiO₂ Nanoparticles Exhibiting Significantly Enhanced Electrical Energy Density

et al. 2009

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Electrical energy storage plays a key role in mobile electronic devices, stationary power systems, and hybrid electric vehicles. [1][2][3] There is a great need for development of new materials with superior electrical energy density since current ceramics and polymers fall significantly short of rising demands in advanced applications. The introduction of inorganic nanoparticles into polymer matrices to form dielectric polymer nanocomposites represents one of the most promising and exciting avenues to this end. [4][5][6][7][8][9][10][11] This approach is motivated by the idea that the combination of ceramic materials of large permittivity with polymers of high breakdown strength could lead to a large energy storage capacity, as energy density is proportional to the product of permittivity and the square of the applied electric field. Moreover, large interfacial areas in the composites containing nanometer scale fillers promote the exchange coupling effect through a dipolar interface layer and result in higher polarization levels and dielectric responses. [12,13] Compared to conventional ceramic materials, polymer-based dielectric materials also offer processing advantages including mechanical flexibility and the ability to be molded into intricate configurations for electronic and electric devices with reduced volume and weight. While most of the current studies on dielectric nanocomposites are focused on the enhancement of dielectric permittivity, few examples have investigated dielectric properties and associated energy densities at high electric fields. [14][15][16] Ferroelectric metal oxides such as Pb(Zr,Ti)O 3 (PZT), Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PMNT), and BaTiO 3 have been popular choices as filler materials in dielectric nanocomposites because of their high permittivities. However, from the energy storage point of view, inclusion of nanoparticles with permittivities on the order of hundreds and even thousands into polymers, which generally possess a permittivity less than 10, might not be desirable for an appreciable increase in energy density. As the filler has a much greater permittivity than the polymer matrix, most of the increase in effective dielectric permittivity comes though an increase in the average field in the polymer matrix with very little of the energy being stored in the high permittivity filler phase.[17] Furthermore, the presence of a large contrast in permittivity between two phases gives rise to a highly inhomogeneous electric field and thus a significantly reduced effective breakdown strength of the composite. [18] In this communication, we report high-energy-density polymer nanocomposites based on surface-functionalized TiO 2 nanocrystals as dopants in a ferroelectric poly(vinylidene fluoride-tertrifluoroethylene-ter-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)). In this approach, the polymer matrix and TiO 2 filler possess comparable dielectric permittivities of 42 and 47, respectively, measured using an inductance, capacitance, resistance (LCR) meter at room temperature and 1 kH...

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“…The ceramic powder was strontium titanate SrTiO , which has a very high permittivity and low loss tangent. According to [10], SrTiO has a relative permittivity of 232 and a loss tangent of 0.0001; however, other sources suggest a higher relative permittivity near 309 [11], [12]. By varying the 0018-926X © 2014 IEEE.…”

Section: Artificial Materials Fabricationmentioning

confidence: 99%

Fabrication, Measurement, and Application of Compressible Artificial Materials

Loeb¹,

Amert²,

Whites

2014

IEEE Trans. Antennas Propagat.

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Fabrication and measurement of compressible composite artificial materials is presented. The composites are mixtures of an elastomer and a ceramic powder with effective relative permittivities ranging from 2.8 to 12.5. The fabrication procedure and its related challenges are detailed along with the benefits inherent to these materials. Accurate characterization of these composites is difficult, since compression during measurement can lead to errors in their extracted permittivities. A proposed solution to this problem uses a density normalization method to remove compression errors from the measured permittivities. Knowledge of the permittivity resulting from specific mixing ratios of the elastomer/ceramic materials benefits designers when creating devices requiring specific dielectric constants. Two microstrip applications are introduced that illustrate the benefits of heterogeneous substrates. One is an edge-loaded patch antenna, and the other is a miniaturized 90 hybrid coupler. The metal area of the patch antenna was miniaturized by nearly 30% with some reduction in gain and an increase in bandwidth. The coupler exhibited a reduction in area of more than 75% over a conventional design with minimum loss in bandwidth.

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Dielectric constant of particles determined by impedance spectroscopy

Cited by 37 publications

References 5 publications

General equivalent circuit derived from capacitance and impedance measurements performed on epitaxial ferroelectric thin films

General equivalent circuit derived from capacitance and impedance measurements performed on epitaxial ferroelectric thin films

Nanocomposites of Ferroelectric Polymers with TiO₂ Nanoparticles Exhibiting Significantly Enhanced Electrical Energy Density

Fabrication, Measurement, and Application of Compressible Artificial Materials

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Dielectric constant of particles determined by impedance spectroscopy

Cited by 37 publications

References 5 publications

General equivalent circuit derived from capacitance and impedance measurements performed on epitaxial ferroelectric thin films

General equivalent circuit derived from capacitance and impedance measurements performed on epitaxial ferroelectric thin films

Nanocomposites of Ferroelectric Polymers with TiO2 Nanoparticles Exhibiting Significantly Enhanced Electrical Energy Density

Fabrication, Measurement, and Application of Compressible Artificial Materials

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Nanocomposites of Ferroelectric Polymers with TiO₂ Nanoparticles Exhibiting Significantly Enhanced Electrical Energy Density