Longitudinal and Transverse Electrocaloric Effects in Glycinium Phosphite Ferroelectric

A modified proton ordering model of glycinium phosphite ferroelectric, which involves the piezoelectric coupling of the proton and lattice subsystems, is used for the investigation of the electrocaloric effect. The model also accounts for the dependence of the effective dipole moment on a hydrogen bond on an order parameter, as well as a splitting of parameters of the interaction between pseudospins in the presence of shear stresses. In the two-particle cluster approximation, the influence of longitudinal and transverse electric fields on components of the polarization vector and the dielectric permittivity tensor, as well as on thermal characteristics of the crystal, is calculated. Longitudinal and transverse electrocaloric effects are studied. The calculated electrocaloric temperature change is quite small, about 1K; however, it can change its sign under the influence of a transverse field.

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Influence of Longitudinal Electric Field on Thermodynamic Properties of NH3CH2COOH·H2PO3 Ferroelectric

Ukrainian Journal of Physics ◽

10.15407/ujpe63.4.350 ◽

2018 ◽

Vol 63 (4) ◽

pp. 350

Author(s):

A. S. Vdovych ◽

I. R. Zachek ◽

R. R. Levitskii

Keyword(s):

Electric Field ◽

Dipole Moments ◽

Quantitative Description ◽

Thermodynamic Characteristics ◽

Polarization Vector ◽

Longitudinal Electric Field ◽

Model Parameters ◽

Cluster Approximation ◽

Static Dielectric Permittivity ◽

Piezoelectric Coupling

Using a modified model of ferroelectric glycine phosphite by considering the piezoelectric coupling with strains e1 within the two-particle cluster approximation, the expressions for the polarization vector, static dielectric permittivity tensor, piezoelectric coefficients, and elastic constants of the crystal in the presence of a longitudinal electric field E2 are calculated. An analysis of the influence of this field on thermodynamic characteristics of the crystal is carried out. The dependence of effective dipole moments on order parameters is taken into account. This allowed us to agree the effective dipole moments in the ferro- and paraelectricphases and to describe the smearing of phase transition under the influence of an electric field. The satisfactory quantitative description of the available experimental data for these characteristics has been obtained at the proper choice of the model parameters.

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Influence of the uniaxial stress $p_2$ and transverse fields $E_1$ and $E_3$ on the phase transitions and thermodynamic characteristics of GPI ferroelectric materials

Mathematical Modeling and Computing ◽

10.23939/mmc2021.03.454 ◽

2021 ◽

Vol 8 (3) ◽

pp. 454-464

Author(s):

R. R. Levitskii ◽

◽

I. R. Zachek ◽

A. S. Vdovych ◽

O. B. Bilenka ◽

...

Keyword(s):

Electric Fields ◽

Thermodynamic Characteristics ◽

Uniaxial Stress ◽

Ferroelectric Materials ◽

Simultaneous Action ◽

Structural Elements ◽

Cluster Approximation ◽

Static Dielectric Permittivity ◽

Piezoelectric Coupling ◽

Transverse Fields

A modified GPI model that accounts for the piezoelectric coupling between the ordered structural elements and the strains $\varepsilon_j$ has been used for studing of effects arising in GPI ferroelectrics under the action of the uniaxial stress $p_{2}$ and electric fields $E_1$ and $E_3$. The polarization vectors and components of static dielectric permittivity are calcucated in the two-particle cluster approximation for mechanically clamped crystal, and piezoelectric and thermal parameters are also determined. The influence of the simultaneous action of the stress $p_{2}$ and fields $E_1$ and $E_3$ on the phase transition and physical characteristics of GPI crystal has been studied.

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An Experimental Investigation on Polypyrrole Films Electro-Polymerized under a High Transverse Electric Field

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.343.77 ◽

2013 ◽

Vol 343 ◽

pp. 77-83

Author(s):

D.M.G. Preethichandra

Keyword(s):

Electric Field ◽

Electric Fields ◽

Transverse Electric ◽

Transverse Field ◽

Transverse Electric Field ◽

Peak Voltage ◽

Cross Sectional ◽

Polypyrrole Films ◽

Transverse Electric Fields ◽

Microscopic Investigations

Polypyrrole films were electrodeposited under different high transverse electric fields, and their film morphologies and functionalities were investigated. The surface morphology at the initial polymerization stage was investigated under AFM and the cross sectional morphologies of fully grown films were investigated by SEM. Both these microscopic investigations revealed the film morphology has been influenced by the applied transverse field. The cyclic voltammetry tests illustrate a reduction in the anodic peak voltage with the increase of transverse field. All these results suggest that the polymer electro-polymerized under a transverse high transverse electric field has some degree of pre-orientation compared to the films synthesized without a transverse electric field.

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Spin current distribution in antiferromagnetic zigzag graphene nanoribbons under transverse electric fields

Scientific Reports ◽

10.1038/s41598-021-96636-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jie Zhang ◽

Eric P. Fahrenthold

Keyword(s):

Electric Fields ◽

Transverse Electric ◽

Graphene Nanoribbons ◽

Spin Current ◽

Differential Resistance ◽

Current Control ◽

Field Analysis ◽

Current Transmission ◽

Transverse Electric Fields ◽

Zigzag Graphene Nanoribbons

AbstractThe spin current transmission properties of narrow zigzag graphene nanoribbons (zGNRs) have been the focus of much computational research, investigating the potential application of zGNRs in spintronic devices. Doping, fuctionalization, edge modification, and external electric fields have been studied as methods for spin current control, and the performance of zGNRs initialized in both ferromagnetic and antiferromagnetic spin states has been modeled. Recent work has shown that precise fabrication of narrow zGNRs is possible, and has addressed long debated questions on their magnetic order and stability. This work has revived interest in the application of antiferromagnetic zGNR configurations in spintronics. A general ab initio analysis of narrow antiferromagnetic zGNR performance under a combination of bias voltage and transverse electric field loading shows that their current transmission characteristics differ sharply from those of their ferromagnetic counterparts. At relatively modest field strengths, both majority and minority spin currents react strongly to the applied field. Analysis of band gaps and current transmission pathways explains the presence of negative differential resistance effects and the development of spatially periodic electron transport structures in these nanoribbons.

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Numerical study of electric field effects on the deformation of two-dimensional liquid drops in simple shear flow at arbitrary Reynolds number

Journal of Fluid Mechanics ◽

10.1017/s0022112009006442 ◽

2009 ◽

Vol 626 ◽

pp. 367-393 ◽

Cited By ~ 32

Author(s):

STEFAN MÄHLMANN ◽

DEMETRIOS T. PAPAGEORGIOU

Keyword(s):

Steady State ◽

Shear Flow ◽

Electric Field ◽

Electric Fields ◽

Simple Shear ◽

Simple Shear Flow ◽

Physical Parameters ◽

Shear Stresses ◽

Two Dimensional ◽

Liquid Drops

The effect of an electric field on a periodic array of two-dimensional liquid drops suspended in simple shear flow is studied numerically. The shear is produced by moving the parallel walls of the channel containing the fluids at equal speeds but in opposite directions and an electric field is generated by imposing a constant voltage difference across the channel walls. The level set method is adapted to electrohydrodynamics problems that include a background flow in order to compute the effects of permittivity and conductivity differences between the two phases on the dynamics and drop configurations. The electric field introduces additional interfacial stresses at the drop interface and we perform extensive computations to assess the combined effects of electric fields, surface tension and inertia. Our computations for perfect dielectric systems indicate that the electric field increases the drop deformation to generate elongated drops at steady state, and at the same time alters the drop orientation by increasing alignment with the vertical, which is the direction of the underlying electric field. These phenomena are observed for a range of values of Reynolds and capillary numbers. Computations using the leaky dielectric model also indicate that for certain combinations of electric properties the drop can undergo enhanced alignment with the vertical or the horizontal, as compared to perfect dielectric systems. For cases of enhanced elongation and alignment with the vertical, the flow positions the droplets closer to the channel walls where they cause larger wall shear stresses. We also establish that a sufficiently strong electric field can be used to destabilize the flow in the sense that steady-state droplets that can exist in its absence for a set of physical parameters, become increasingly and indefinitely elongated until additional mechanisms can lead to rupture. It is suggested that electric fields can be used to enhance such phenomena.

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