scholarly journals Theoretical prediction of electrocaloric effect based on non-linear behaviors of dielectric permittivity under temperature and electric fields

AIP Advances ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 117134 ◽  
Author(s):  
Hongbo Liu ◽  
Xue Yang
Keyword(s):  
Dielectric Permittivity ◽  
Theoretical Prediction ◽  
Electric Fields ◽  
Electrocaloric Effect ◽  
Non Linear

Relation between dielectric permittivity and electrocaloric effect under high electric fields in the Pb(Mg1/3Nb2/3)O3-based ceramics

2020 ◽  
Vol 127 (18) ◽  
pp. 184102
Author(s):  
Lovro Fulanović ◽  
Andraž Bradeško ◽  
Nikola Novak ◽  
Barbara Malič ◽  
Vid Bobnar
Keyword(s):  
Dielectric Permittivity ◽  
Electric Fields ◽  
Electrocaloric Effect ◽  
High Electric Fields

scholarly journals Non-linear and non-local behaviour in spontaneously electrical solids

2018 ◽  
Vol 20 (7) ◽  
pp. 5112-5116 ◽  
Author(s):  
M. Roman ◽  
S. Taj ◽  
M. Gutowski ◽  
M. R. S. McCoustra ◽  
A. C. Dunn ◽  
...  
Keyword(s):  
Electric Fields ◽  
Dipole Orientation ◽  
Local Behaviour ◽  
Non Linear ◽  
Non Local

We show that solids displaying spontaneous dipole orientation possess quite general non-local and non-linear characteristics expressed through their internal electric fields.

Effects of Non-Linearity of the Momentum Conservation Equation During Electrokinetic Transport in Nano and Microchannels

2010 ◽  
Author(s):  
Subir Bhattacharjee ◽  
Noor Al Quddus
Keyword(s):  
Porous Media ◽  
Electric Fields ◽  
Stokes Equations ◽  
Momentum Conservation ◽  
Conservation Equation ◽  
Small Scale ◽  
Electrokinetic Transport ◽  
Electrokinetic Flow ◽  
Non Linear ◽  
Momentum Conservation Equation

Electrokinetic transport phenomena, such as electroosmosis, streaming potential, electrophoresis, and sedimentation potential, are central to many micro- and nano-channel flows. During continuum modeling of such phenomena, incorporation of the electrical body force term can make the fluid momentum conservation equation highly non-linear. This non-linearity is often ignored in small-scale electrokinetic flow modeling because of our implicit reliance on the linearity of the Stokes equations for low Reynolds number flows. In this paper, ramifications of this non-linear Stokes equation in electrokinetic flows will be described with examples of our recent studies on pressure driven flows through porous media for electrokinetic power generation, electroosmotic flow of charged entities in nanochannels, and flow of DNA through self-assembled porous media under pulsed electric fields.

Effect of Dielectric Imperfections on the Electroactive Deformations of Polar Dielectric Elastomers

2019 ◽  
Vol 86 (8) ◽  
Author(s):  
Yanhui Jiang ◽  
Yang Liu
Keyword(s):  
Dielectric Permittivity ◽  
Shear Modulus ◽  
Electric Fields ◽  
Nonlinear Deformation ◽  
Dielectric Elastomers ◽  
Inhomogeneous Deformation ◽  
Polar Dielectric ◽  
Polar Groups ◽  
Deformation Stability ◽  
Potential Applications

We find that the ratio of dielectric permittivity to shear modulus is linearly related to the number of polar groups per polymer chain in polar dielectric elastomers (PDEs). Our discovery is verified via computational modeling and validated by experimental evidences. Based on the finding, we introduce the new concept of dielectric imperfection (DI) and provide some physical insights into understanding it through demonstrating the large nonlinear deformation of PDEs with DIs under electric fields. The results show remarkable DI-induced inhomogeneous deformation and indicate that the size and dielectric permittivity of DIs have a significant impact on the deformation stability of PDEs under electric fields. With this concept, we propose some potential applications of PDEs with DIs.

scholarly journals The Dispersion of Strong Field Dielectric Permittivity in (1-x)PMN-(x)PT Ceramics

2011 ◽  
Vol 56 (4) ◽  
pp. 1199-1203 ◽  
Author(s):  
P. Wawrzała ◽  
R. Skulski
Keyword(s):  
Dielectric Permittivity ◽  
Hysteresis Loop ◽  
Electric Fields ◽  
Strong Field ◽  
Low Frequency ◽  
Frequency Dispersion ◽  
Strong Electric Fields

The Dispersion of Strong Field Dielectric Permittivity in (1-x)PMN-(x)PT CeramicsWe propose the method of analysis of the dielectric permittivity measured in very strong electric fields. The method is based on the numeric calculations of derivative fromP - Ehysteresis loop. Such investigations have been performed for PMN-PT ceramics at various temperatures and frequencies. As a result we analyze the low frequency dispersion of the strong field dielectric permittivity.

In situinvestigation of the non-linear optical crystal rubidium titanyl arsenate, RbTiOAsO4, under applied electric field using X-ray imaging

2007 ◽  
Vol 40 (3) ◽  
pp. 505-512 ◽  
Author(s):  
D. Walker ◽  
P. A. Thomas ◽  
P. Pernot-Rejmánková ◽  
J. Baruchel
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Surface Region ◽  
Uniform Field ◽  
Linear Optics ◽  
Near Surface ◽  
X Ray ◽  
Non Linear ◽  
Linear Optical ◽  
Section Topography

Recent work on the non-linear optical single-crystal rubidium titanyl arsenate (RbTiOAsO4, RTA) has shown that it exhibits behaviour consistent with a ferroelectric semiconductor under large applied electric fields, with the development of a non-uniform field in the near-surface region. To confirm aspects of the proposed model, the behaviour of 001 slices of initially single-domain RTA, patterned with periodic Ag electrodes of spacing 38 µm, as for periodic poling in non-linear optics, were investigated using synchrotron X-ray section topography with the electric field appliedin situwhile under X-ray illumination at the ID19 topography beamline of the ESRF, Grenoble. The results of white-beam section topography as both a function of crystal to film distance, and under DC voltage are reported, confirming that there is a bending of the planes in the near-surface region. The strain in the near-surface region was examined directly using high-resolution monochromatic X-ray section topography. This revealed an extensive strain of 3 (±1) × 10−4at 1 kV, indicating that the electrostrictive coefficient, γ3333, in RTA is positive in sign.

2D pore-scale simulation of wide-band electromagnetic dispersion of saturated rocks

Geophysics ◽  
2007 ◽  
Vol 72 (3) ◽  
pp. F97-F110 ◽  
Author(s):  
Emmanuel Toumelin ◽  
Carlos Torres-Verdín
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Electric Fields ◽  
Electromagnetic Property ◽  
Wide Band ◽  
Geometrical Parameters ◽  
Pore Scale ◽  
Porous Rocks ◽  
Pore Connectivity ◽  
Scale Properties

Effective medium theories (EMTs) are invoked routinely to interpret multifrequency dispersions of dielectric permittivity and electrical conductivity of saturated rocks. However, EMTs exhibit limitations that substantially restrict their validity for petrophysical interpretation. For instance, pore connectivity is of significant interest in the study of subsurface reservoirs, but no existing EMT includes it as an explicit property in the analysis of kilohertz- to gigahertz-range dielectric measurements. We introduce a new approach to quantify the effects of pore geometry and connectivity on the kilohertz-gigahertz frequency dispersion of dielectric permittivity and electrical conductivity of clay-free porous rocks. This approach is based on the numerical solution of the internal electric fields within submicron-resolution pore maps constructed with grain and rock pixels. The discrepancy between the internal fields and electrical currents calculated for ahomogeneous scatterer and those calculated for a given pore map is minimized to yield the effective electrical conductivity and dielectric constant for that pore map. This minimization is performed independently for each frequency and is verified to agree implicitly with Kramers-Kronig's causality relationships. We show that EMTs only predict an average dispersion for given microscopic geometrical parameters (e.g., porosity, pore eccentricity), whereas individual realizations honoring the same parameters are associated with dispersion about average values predicted by EMTs. Unlike any EMT prediction, we show that pore connectivity plays a major role in both the shape and amplitude of wide-band electromagnetic property dispersions. The simulation procedure introduced in this paper provides a systematic method to assess the sensitivity of a multitude of pore-scale properties on the macroscopic wide-band dielectric dispersion of saturated rocks.

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