scholarly journals Intrinsic and extrinsic contributions in non-linearity dielectric response of (Bi0.5Na0.3K0.2)TiO3-(Ba0.8Ca0.2)TiO3 based SrTiO3 ceramics driven by Rayleigh model

2021 ◽  
Author(s):  
Abdelrazek Mahmoud ◽  
Afaf M. Babeer
Keyword(s):  
Phase Transition ◽  
Domain Wall ◽  
Grain Morphology ◽  
Domain Wall Motion ◽  
High Amplitude ◽  
Solution Technique ◽  
Two Phase ◽  
Distortion Effect ◽  
Crossover Phase ◽  
Different Temperatures

Abstract Pb-free ceramics of [(0.95-x)(Bi0.5Na0.3K0.2)TiO3-0.05(Ba0.8Ca0.2)TiO3 doped x(SrTiO3) (0.0 ≤ x ≤ 0.2) were prepared by solid solution technique. The effect of ST content on the crystal structure and morphology of the sintered ceramics were systemically investigated. Crossover phase transition from ferroelectric to relaxor accompanied by changes in the shape of grain morphology were observed by increasing ST-content. The phase crossover is caused by oxygen vacancies and 1attice distortion effect. The electrical properties for virgin and poled samples were investigated. All virgin samples belong (x ≤ 0.15) showed present ferroelectric to relaxor diffused phase transition however ST = 0.2, only relaxor to paraelectric phase transition was detected in whole range of temperature. The poled sample of ST = 0.2 showed present two phase transition similar to (ST ≤ 0.15) denote domain grow caused by domain wall displacement at high amplitude of electric field. The polarization response was studied under sub-switching cyclic of electric fie1ds at different temperatures. The non-linearity behavior showed both of ferroe1ectric and relaxor phase dominated by Rayleigh-type dynamic. The results suggest that in ferroelectric phase, the extrinsic contribution caused by domain wall motion is responsible for majority of dielectric contributions while in relaxor phase, the majority of dielectric contribution are comes from intrinsic contribution caused by lattice distortion effect. Corresponding author: [email protected]

scholarly journals Effect of Electric Field and Temperature on Average Structure and Domain Wall Motion in 0.93Bi0.5Na0.5TiO3-0.07BaTiO3Ceramic

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Jian Wang ◽  
Yun Liu ◽  
Andrew Studer ◽  
Lasse Norén ◽  
Ray Withers
Keyword(s):  
Phase Transition ◽  
Domain Wall ◽  
Electric Field ◽  
Wall Motion ◽  
Domain Wall Motion ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Temperature Phase Transition ◽  
Diffraction Patterns

In situneutron powder diffraction patterns and dielectric spectra of 0.93Bi0.5Na0.5TiO3-0.07BaTiO3ceramic were investigated under different electrical fields and temperatures. An electric-field-induced phase transition from metrically cubic to metrically tetragonal, associated with strong domain wall motion, occurs. Such induced phase and domain wall motion are unchanged until the high-temperature phase transition occurs from metrically tetragonal to metrically cubic. All these changes are irrelevant to the observed depolarization temperature (75°C). The depolarization behaviour is thus suggested to be associated with the local structure caused by the octahedral tilt twinning disorder.

Electrical Probing of Magnetic Phase Transition and Domain Wall Motion in Single-Crystalline Mn5Ge3 Nanowire

Nano Letters ◽  
2012 ◽  
Vol 12 (12) ◽  
pp. 6372-6379 ◽  
Author(s):  
Jianshi Tang ◽  
Chiu-Yen Wang ◽  
Wanjun Jiang ◽  
Li-Te Chang ◽  
Yabin Fan ◽  
...  
Keyword(s):  
Phase Transition ◽  
Domain Wall ◽  
Magnetic Phase Transition ◽  
Wall Motion ◽  
Magnetic Phase ◽  
Domain Wall Motion ◽  
Single Crystalline

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

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