Electron Holographic Characterization of Ferroelectric Thin Films

1992 ◽  
Vol 284 ◽  
Author(s):  
Xiao Zhang ◽  
David C. Joy
Keyword(s):  
Thin Films ◽  
Domain Wall ◽  
Domain Walls ◽  
Ferroelectric Domain ◽  
Electron Holography ◽  
Contrast Imaging ◽  
Thin Specimen ◽  
Wall Width ◽  
Domain Wall Width

ABSTRACTIn this paper we will present recent experimental results, using electron holography and electron interferometry, of studies of ferroelectric domain walls in BaTiO3 thin films. Unlike conventional TEM diffraction contrast imaging of ferroelectrics, the new technique that we have developed not only allows direct visualization of ferroelectric domain walls and electrostatic field distributions in the vicinity of the domain wall, but also enables quantitative measurement of domain wall width and local polarization. We have measured 90° domain wall width to be between 20 to 50 Å for a BaTiO3 thin specimen. The variation of polarization across the domain wall will be shown to be close to that predicted by the Zhirnov model. The value of the measured spontaneous polarization is about 1.5×10−5 C/cm2, which is closed to the bulk macroscopically measured value.

Application of electron holography to ferroelectric study

1993 ◽  
Vol 51 ◽  
pp. 1092-1093
Author(s):  
X. Zhang ◽  
D. C. Joy ◽  
L. F. Allard ◽  
T. A. Nolan
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
Ferroelectric Domain ◽  
Electron Holography ◽  
Local Domain ◽  
Holographic Method ◽  
Wall Area ◽  
Weak Phase ◽  
Wall Structures ◽  
Essential Input

With the development of FE TEM, electron holography becomes a reality to materials scientists, which opens a new window for materials study. Weak phase objects, such as a thin transparent specimen or an electric or a magnetic field, which have little or no effect on the intensity of the transmitted wave, can readily be observed via holography because of the phase shift that they produce. Application of the electron holographic method has been extended to the study of ferroelectric domain wall structures. This work presents the most recent results in this area.Polarization gradients within domain walls are extremely important for the understanding of the extrinsic elastio-dielectric properties of ferroelectrics. Electron holographic studies of the local domain wall profiles provide essential input parameters for phenomenological theories of domain structure and of the macroscopic properties derived from the theories. Figure 1(a) is an electron hologram of the ferroelectric (BaTiO3) 90° domain wall area.

A Discrete Phase Model for Ferroelectric Domain Evolution

2011 ◽  
Author(s):  
Wen Dong ◽  
David Pisani ◽  
Christopher S. Lynch
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
Landau Equation ◽  
Phase Method ◽  
Discrete Phase Model ◽  
Wall Width ◽  
Domain Evolution ◽  
Discrete Phase ◽  
Gradient Energy ◽  
Domain Wall Width

Discrete phase modeling utilizes a finite element framework with a Landau-Devonshire type multi-well potential as a material subroutine to model domain evolution in ferroelectrics. The time-dependent Ginzburg-Landau equation with polarization as an order parameter governs evolution of polarization. In the discrete phase method, the domain wall width is not controlled by an adjustable parameter, the gradient energy term used in phase field models; rather, it is controlled by a balance between mechanical, structural, and electrostatic contributions to the free energy. The effect of this energy balance on the resulting domain wall width of 90° and 180° tetragonal domain walls is discussed and examples are presented.

The influence of 180° ferroelectric domain wall width on the threshold field for wall motion

2008 ◽  
Vol 104 (8) ◽  
pp. 084107 ◽  
Author(s):  
Samrat Choudhury ◽  
Yulan Li ◽  
Nozomi Odagawa ◽  
Aravind Vasudevarao ◽  
L. Tian ◽  
...  
Keyword(s):  
Domain Wall ◽  
Wall Motion ◽  
Ferroelectric Domain ◽  
Threshold Field ◽  
Wall Width ◽  
Domain Wall Width

scholarly journals Domain Walls in the Early Universe and Generation of Matter and Antimatter Domains

2018 ◽  
Vol 182 ◽  
pp. 02048
Author(s):  
A.D. Dolgov ◽  
S.I. Godunov ◽  
A.S. Rudenko
Keyword(s):  
Scalar Field ◽  
Domain Wall ◽  
Early Universe ◽  
Parameter Space ◽  
Related Problem ◽  
Domain Walls ◽  
Numerical Study ◽  
Parameter Region ◽  
Wall Width ◽  
Domain Wall Width

We present a model where it is possible to generate cosmologically large domains of matter and antimatter separated by cosmologically large distances. Domain walls existed only in the early universe and later they disappeared. So the problem of domain walls in this model does not exist. These features are achieved through a postulated form of interaction between inflaton and a new scalar field. This scenario inspired a study of the related problem - evolution of the domain wall width in expanding universe. According to classical results there is a region of parameter space where the solutions with constant physical width exist. Numerical study of the problem demonstrates that initial configurations tend to these solutions with time. However, we have found that the wall width can grow exponentially outside of that parameter region.

Imaging of ferroelectric domain walls by electron holography

1992 ◽  
Vol 50 (1) ◽  
pp. 246-247
Author(s):  
Xiao Zhang
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Domain Walls ◽  
Ferroelectric Domain ◽  
Object Wave ◽  
Electron Holography ◽  
High Resolution Imaging ◽  
Quantitative Measurements ◽  
Resolution Imaging ◽  
Electron Microscopes

Electron holography has recently been available to modern electron microscopy labs with the development of field emission electron microscopes. The unique advantage of recording both amplitude and phase of the object wave makes electron holography a effective tool to study electron optical phase objects. The visibility of the phase shifts of the object wave makes it possible to directly image the distributions of an electric or a magnetic field at high resolution. This work presents preliminary results of first high resolution imaging of ferroelectric domain walls by electron holography in BaTiO3 and quantitative measurements of electrostatic field distribution across domain walls.

Peierls “Washboard” Controls Dynamics of the Domain Walls in Molecular Ferrimagnets

2015 ◽  
Vol 233-234 ◽  
pp. 55-59
Author(s):  
Marina Kirman ◽  
Artem Talantsev ◽  
Roman Morgunov
Keyword(s):  
Domain Wall ◽  
Crystal Lattice ◽  
Domain Walls ◽  
Low Frequency ◽  
Domain Wall Motion ◽  
Lattice Parameter ◽  
Structural Defects ◽  
Crystal Lattice Parameter ◽  
Wall Width ◽  
Debye Relaxation

The magnetization dynamics of metal-organic crystals has been studied in low frequency AC magnetic field. Four modes of domain wall motion (Debye relaxation, creep, slide and over - barrier motion (switching)) were distinguished in [MnII(H(R/S)-pn)(H2O)] [MnIII(CN)6]⋅2H2O crystals. Debye relaxation and creep of the domain walls are sensitive to Peierls relief configuration controlled by crystal lattice chirality. Structural defects and periodical Peierls potential compete in the damping of the domain walls. Driving factor of this competition is ratio of the domain wall width to the crystal lattice parameter.

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