Electrical properties of BaTiO₃nanoparticles in poly(ether imide)

Abstract

The relative permittivity has been measured at audio frequencies and low temperatures for nanocomposites composed of poly(ether imide) (PEI) and BaTiO3 nanoparticles, the nanoparticles in a cavity and polycrystalline BaTiO3. The data at room temperature, for the real part of the relative permittivity versus nanoparticle content of the heat-treated nanocomposites, are found to follow a recently proposed modified Hanai equation. Also, a low-temperature relaxation region (in the vicinity of 20 K) is found in the heat-treated nanocomposites. This relaxation region is also observed in measurements on the nanoparticles packed in a cavity and for the polycrystalline BaTiO3 materials. A relaxation associated with water in the PEI is observed in the as-prepared nanocomposites. Finally, the breakdown strength of the heat-treated nanocomposites is found to decrease as the nanoparticle content increases. Microstructure-level simulations of electric field statistics were carried out and show that matrix field intensification cannot account for all of the variation of breakdown strength with nanoparticle concentration.

A highly scalable dielectric metamaterial with superior capacitor performance over a broad temperature

“…Several approaches have been investigated in the past to raise the dielectric constant K of polymer-based dielectrics and hence improve the energy density. For example, nanocomposites in which high volume loading (>15 volume %) of high-dielectric constant nanofillers (K > 1000) is added to a polymer matrix have been widely studied to raise the dielectric constant (7,(13)(14)(15). The rationale for this approach is based on the assumption that the composites can maintain high breakdown field E of the polymer matrix, and hence, a high U e can be obtained.…”

“…The rationale for this approach is based on the assumption that the composites can maintain high breakdown field E of the polymer matrix, and hence, a high U e can be obtained. However, the large dielectric contrast between the nanofillers and polymer matrix and high volume loading of nanofillers required to raise K of the composites result in the intensification of local electric fields in the polymer matrix, leading to a large reduction of the electric breakdown strength (15)(16)(17). To mitigate this local field effect, the surfaces of high-K nanofillers have been modified, for example, to form core-shell structures that reduce the local field strength so that the breakdown strength of the nanocomposites approaches that of the polymer matrix (18,19).…”

Investigation into the Atomistic Scale Mechanisms Responsible for the Enhanced Dielectric Response in the Interfacial Region of Polymer Nanocomposites

“…Alternatively, ε can be increased by adding high permittivity inorganic nanofillers to a polymer matrix. ,,,,, Adding inorganic nanofillers to a polymer matrix has been demonstrated to increase the free volume, which improves the dipole coupling and thereby enhances the dielectric properties . BaTiO 3 , − Al 2 O 3 , , MgO, and SiO 2 , nanoparticles have been used as nanofillers in polymer matrixes to enhance ε in nanocomposites. However, large concentrations of these nanofillers are associated with a reduction in the breakdown strength under high voltage conditions .…”

Fabrication of barium titanate/acrylonitrile-butadiene styrene/poly(methyl methacrylate) nanocomposite films for hybrid ferroelectric capacitors

“…This technique became popular in the past few years and consists of encasing ferroelectric ceramic llers into a polymeric matrix. 1,2,[7][8][9] As such, several methods have recently developed for the fabrication of ferroelectric nanoparticles-based polymer composites. In most cases, the addition of non-functionalized inorganic nanoparticles to polymers is accompanied by the clustering and aggregation of the nanoparticles, phase separation and the formation of voids, which are detrimental to the dielectric properties of the nanocomposites as a result of the increase of dielectric loss and current leakage.…”

“…In most cases, the addition of non-functionalized inorganic nanoparticles to polymers is accompanied by the clustering and aggregation of the nanoparticles, phase separation and the formation of voids, which are detrimental to the dielectric properties of the nanocomposites as a result of the increase of dielectric loss and current leakage. 8,9 The incompatibility between non-functionalized inorganic nanoparticles and the organic polymer can be primarily ascribed to the intrinsic high surface energy of the nanoparticles, which weakens drastically the adhesion in ller/polymer interface. [9][10][11] Two different approaches have proven to be promising to improve the strength of interfacial adhesion in biphasic polymer nanocomposites without deteriorating the macroscopic dielectric properties.…”