Diffraction from disordered one-dimensional islands with domain boundaries: Intensity behavior for various statistical approximations

1987 ◽  
Vol 35 (12) ◽  
pp. 6004-6016 ◽  
Author(s):  
J. Evans ◽  
R. S. Nord
Keyword(s):  
One Dimensional ◽  
Domain Boundaries

MISSING "SHEETS" IN THE RECIPROCAL SPACE REPRESENTATION OF THE DISORDERED SURFACE WITH ONE-DIMENSIONAL DOMAIN BOUNDARIES

2001 ◽  
Vol 08 (05) ◽  
pp. 509-511
Author(s):  
E. S. TOK ◽  
J. ZHANG ◽  
I. KAMIYA ◽  
M. H. XIE ◽  
J. H. NEAVE ◽  
...  
Keyword(s):  
Fractional Order ◽  
Optical Transmission ◽  
Reciprocal Space ◽  
Space Representation ◽  
Selection Rules ◽  
One Dimensional ◽  
Kinematic Theory ◽  
Domain Boundaries ◽  
Reconstructed Surface ◽  
Dimensional Domain

One-dimensional disorder in a reconstructed surface can give rise to sheetlike structures in reciprocal space. For disorder caused by one-dimensional domain boundaries such as those that occur on the GaAs {100}(2 × 4) surface, sheetlike structures are only present at fractional order diffraction features. The absence of these sheets at integral diffraction features is explained using kinematic theory of diffraction and "selection rules" for these sheetlike structures are established. Applications of these rules are demonstrated using optical transmission diffraction.

scholarly journals Effects of Domain Boundaries on the Diffraction Patterns of One Dimensional Structures

2016 ◽  
Author(s):  
Frederic Timmer ◽  
Joachim Wollschläger
Keyword(s):  
Rare Earth ◽  
Diffraction Pattern ◽  
Diffraction Theory ◽  
Model Systems ◽  
Silicide Formation ◽  
One Dimensional ◽  
Domain Boundaries ◽  
Different Types ◽  
Diffraction Patterns ◽  
Surface Technique

Motivated by diffraction experiments on the 23×3R30∘ reconstructed Si(111) due to deposition of rare earth elements (Dy, Tb) and silicide formation we analyse the splitting and non-splitting of superstructure spots. For this purpose, we model diffraction patterns for one dimensional structures generated by the binary surface technique and use supercell models to keep the analysis simple. Diffraction pattern are calculated in the framework of the kinematical diffraction theory and they are analyzed as a function of the domains and domain boundaries. Basic properties of the diffraction pattern are analyzed for model systems of a two-fold and a three-fold periodicity. The rules derived from these calculations are applied to the "real-world" system of Si(111)-(23×3R30∘)-RESi2 (RE = Dy or Tb). Depending on the combination of domains and domain boundaries of different types a plethora of different features are observed in the diffraction patterns. These are analyzed to determine the sizes of both domain boundaries and domains from experimentally observed splitting of specific superstructure spots.

Synchrotron radiation topographic observation of KTiOPO4crystals under an electric field

1999 ◽  
Vol 32 (2) ◽  
pp. 187-192 ◽  
Author(s):  
W. J. Liu ◽  
S. S. Jiang ◽  
Y. Ding ◽  
X. S. Wu ◽  
J. Y. Wang ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Electric Field ◽  
Lattice Distortion ◽  
Polar Axis ◽  
Anisotropic Conductivity ◽  
One Dimensional ◽  
Governing Factor ◽  
Domain Boundaries ◽  
Local Accumulation

In situwhite-beam synchrotron radiation topographic observations under an electric field have been made on the KTiOPO4(KTP) family of crystals. The investigation shows a strong enhancement of diffracted intensity forhklreflections (l ≠ 0) and topographic contrast in the form of fine striations when the external electric field is parallel to the polar axis. Several kinds of doped and undoped samples with various grown-in defects, such as domain boundaries, growth striations, growth-sector boundaries, dislocations,etc., have been studied in detail. The results suggest that these defects have very little effect on the field-induced striations. It is believed that the movement of K^+ ions driven by the electric field leads to a local accumulation of charges and a lattice distortion. The strongly anisotropic conductivity is a governing factor in the explanation of the field-related phenomena in this kind of quasi-one-dimensional conductor.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

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