scholarly journals The effect of an AC electric field on the dielectric properties of Pb(Mg1/3Nb2/3)O3 ceramic

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
E.C. Lima ◽  
J.D.S. Guerra ◽  
E.B. Araujo
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Electric Field ◽  
Statistical Model ◽  
Dielectric Response ◽  
Freezing Temperature ◽  
Dielectric Dispersion ◽  
Electrical Field ◽  
Ac Electric Field ◽  
Applied Electrical Field

The dynamic dielectric response of Pb(Mg1/3Nb2/3 )O3 ceramic was experimentally studied as a function of the EAC amplitude field. An increase in real dielectric permittivity was obtained by increasing the applied electrical field within the investigated temperature range for frequencies below 10 kHz. The temperature of maximum dielectric permittivity and freezing temperature decreased with an increase in E AC. Nonlinear permittivity was studied and found to behave similarly to freezing temperature. A statistical model was used to fit the dielectric dispersion of real dielectric permittivity with temperature and frequency. The results are discussed in terms of different factors’ contributions to dielectric permittivity under different EAC field conditions.

THE EFFECT OF ELECTRIC FIELD ON THE DIELECTRIC PERMITTIVITY OF BST/STO SUPERLATTICE

2013 ◽  
Vol 27 (10) ◽  
pp. 1350066 ◽  
Author(s):  
ZHI-GAO ZUO ◽  
FU-RI LING ◽  
DAN LI ◽  
JIN-SONG LIU ◽  
JIAN-QUAN YAO
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Electric Field ◽  
External Electric Field ◽  
Ferroelectric Properties ◽  
Transformation Strain ◽  
Elastic Interaction ◽  
Dielectric Behavior ◽  
Electrical Field ◽  
External Electrical Field

A nonlinear thermodynamic model is developed for investigating the effect of external electric field on the dielectric properties of Ba 0.6 Sr 0.4 TiO 3/ SrTiO 3( BST / STO ) super-lattice. The transformation strain induced by the external electrical field are analyzed and calculated. It is found that the dielectric and ferroelectric properties of the ( BST / STO ) superlattice vary substantially with the interlayer elastic interaction caused by the external electrical field. The results also provide better understanding of the dielectric behavior of BST / STO superlattice with external electric field and a necessary step in the development of the general nonlinear theory.

Spinal neurite reabsorption and regrowth in vitro depend on the polarity of an applied electric field

Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 31-41
Author(s):  
C.D. McCaig
Keyword(s):  
Electric Field ◽  
Neural Tube ◽  
Applied Field ◽  
Growth Cones ◽  
Individual Growth ◽  
Electrical Field ◽  
Field Reversal ◽  
Specific Change ◽  
Applied Electrical Field

Retraction and regrowth of frog neural tube neurites have been studied in vitro in control cultures and in the presence of a small, continuously applied electrical field. In control cultures, some degree of retraction was seen in 39% of neurites while 7% were reabsorbed completely. Reabsorption of anodal-facing neurites was at least twice as common, with 67% showing some retraction and 17% almost totally reabsorbed. Cathodal-facing neurites were spared from retraction. Following extreme reabsorption of anodal-facing neurites, reversal of the electric field promoted regeneration in 47% (9/19) of cases studied. growth cone morphology also was determined by the polarity of the applied field. Anodal-facing growth cones had fewer filopodia than cathodal-facing growth cones sharing the same cell body. Field reversal induced a polarity-specific change in filopodia number on individual growth cones: a shift from anodal to cathodal increased filopodia numbers and vice versa. Some possible mechanisms involved and the significance of these results are discussed.

Dielectric Properties of Dielectrophoretically Aligned ZnO-PDMS Composites

2016 ◽  
Author(s):  
Md Abdulla Al Masud ◽  
Zoubeida Ounaies
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Electric Field ◽  
Mechanical Analysis ◽  
High Yield ◽  
Chemical Route ◽  
Random Composites ◽  
Pdms Elastomer ◽  
Random Dispersion ◽  
Zno Rods

ZnO based polymer composite materials are of great interest because of their excellent electrical, optical, semiconductor and biocompatible properties. In this study, we synthesize anisotropic composites of aligned ZnO rods in polydimethylsiloxane (PDMS) elastomer and study their dielectric properties as a function of applied electric field and frequency. Submicron ZnO rods are synthesized using an inexpensive, high yield chemical route. Washed and purified ZnO rods are then aligned in uncured PDMS at different electric field and frequency. We find that under electric field, ZnO rotates with their long axis in the direction of the electric field and before coalescing form chains in the silicone elastomer. From the optical microscopy images and in situ dielectric measurements, the best alignment parameters are found at 4 kV/mm and 10 kHz. These conditions are then selected to prepare aligned ZnO-PDMS composites. Complete curing of composites is confirmed using dynamic mechanical analysis (DMA). Our results show that aligned ZnO in uncured PDMS exhibit higher dielectric permittivity compared to random dispersion with the same composition. For the cured ZnO-PDMS composites, dielectric permittivity increases by 80% compared to random composites.

scholarly journals Dielectric properties of Bi12SiO20 crystals doped with Al

2019 ◽  
Vol 27 (2) ◽  
pp. 85-88
Author(s):  
T. V. Panchenko ◽  
L. M. Karpova
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Electric Field ◽  
Hysteresis Loops ◽  
Complex Dielectric Permittivity ◽  
Temperature Range ◽  
Dielectric Matrix ◽  
Before And After ◽  
Frequency Dependences

The temperature-frequency dependences of the complex dielectric permittivity ε and the voltage-farad characteristics of undoped and aluminum doped Bi12SiO20 crystals are studied before and after their polarization. It is shown that Al ions in the Bi12SiO20 dielectric matrix provide a significant increase as well as nonlinearity of ε in the temperature range 300 – 800 K and electric field strengths Е = 103 – 104 V/cm. It is shown that polarization causes the appearance of dielectric hysteresis loops. Al impurity significantly affects the appearance and parameters of these loops. The role of Al ions in increasing the contribution of the quasi-dipole mechanism in the polarization processes is revealed.

Anomalous Broad Dielectric Dispersion of 0.4PZN-0.3PSN-0.3PZN Relaxor Ceramics at Lower Temperatures

2006 ◽  
Vol 514-516 ◽  
pp. 216-220
Author(s):  
Juras Banys ◽  
Jan Macutkevic ◽  
Algirdas Brilingas ◽  
Vytautas Samulionis ◽  
K. Bormanis ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Bias Field ◽  
Dielectric Dispersion ◽  
Dielectric Losses ◽  
Low Frequencies ◽  
External Bias ◽  
Very High ◽  
Maximum Permittivity

Dielectric properties of 0.4PbZn1/3Nb2/3O3-0.3PbSc1/2Nb1/2O3-0.3PbMg1/3Nb2/3O3- (0.4PZN- 0.3PSN-0.3PMN) ceramics are presented for 200 < T < 500 K and 20 Hz < ν < 1 MHz. Dielectric constant is very high (more 14000) in the vicinity of the peak. Anomalous broad dielectric relaxation have been observed near the temperature of the maximum permittivity, Tm (at 1 kHz). External bias field considerably lowers the value of dielectric losses at low frequencies due to decrease of polar nano regions contribution to the dielectric permittivity.

Self-Assembly and Manipulation of Particles on Drop Surfaces

2014 ◽  
Author(s):  
Edison C. Amah ◽  
Kinnari Shah ◽  
Ian S. Fischer ◽  
Pushpendra Singh
Keyword(s):  
Dielectric Properties ◽  
Electric Field ◽  
Self Assembly ◽  
Hydrodynamic Force ◽  
Hydrodynamic Forces ◽  
Ac Electric Field ◽  
Induced Motion

It was recently shown by us that particles distributed on the surface of a drop can be concentrated at the poles or equator of the drop by subjecting it to a uniform ac electric field. The dielectrophoretic and hydrodynamic forces which cause the motion of particles depend on the parameters such as the particles’ and drop’s radii, the dielectric properties of the fluids and particles, and the frequency of the electric field. The hydrodynamic force, which arises because of the induced motion in the liquids, is the main focus of this paper. We show that it can be used to control the distribution of particle monolayers on the surface of a drop.

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