Impact of local atomic stress on oxygen segregation at tilt boundaries in silicon

There have Been a number of studies of low-angle, θ < 4°, [10] tilt boundaries in the diamond lattice. Dislocations with Burgers vectors a/2<110>, a/2<112>, a<111> and a<001> have been reported in melt-grown bicrystals of germanium, and dislocations with Burgers vectors a<001> and a/2<112> have been reported in hot-pressed bicrystals of silicon. Most of the dislocations were found to be dissociated, the dissociation widths being dependent on the tilt angle. Possible dissociation schemes and formation mechanisms for the a<001> and a<111> dislocations from the interaction of lattice dislocations have recently been given.The present study reports on the dislocation structure of a 10° [10] tilt boundary in chemically vapor deposited silicon. The dislocations in the boundary were spaced about 1-3nm apart, making them difficult to resolve by conventional diffraction contrast techniques. The dislocation structure was therefore studied by the lattice-fringe imaging technique.

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TEM Study of a Tilt Boundary in Hot-Pressed Silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097454 ◽

1981 ◽

Vol 39 ◽

pp. 160-161

Author(s):

C. B. Carter ◽

J. Rose ◽

D. G. Ast

Keyword(s):

Electron Diffraction ◽

Imaging Technique ◽

Interface Structure ◽

Large Area ◽

Weak Beam ◽

Lattice Fringe ◽

Electron Diffraction Technique ◽

Tilt Boundaries ◽

Beam Technique ◽

Twist Boundaries

The hot-pressing technique which has been successfully used to manufacture twist boundaries in silicon has now been used to form tilt boundaries in this material. In the present study, weak-beam imaging, lattice-fringe imaging and electron diffraction techniques have been combined to identify different features of the interface structure. The weak-beam technique gives an overall picture of the geometry of the boundary and in particular allows steps in the plane of the boundary which are normal to the dislocation lines to be identified. It also allows pockets of amorphous SiO2 remaining in the interface to be recognized. The lattice-fringe imaging technique allows the boundary plane parallel to the dislocation to be identified. Finally the electron diffraction technique allows the periodic structure of the boundary to be evaluated over a large area - this is particularly valuable when the dislocations are closely spaced - and can also provide information on the structural width of the interface.

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High-resolution x-ray analysis of dislocation networks nn tilt boundaries

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105126 ◽

1988 ◽

Vol 46 ◽

pp. 612-613

Author(s):

J. R. Michael ◽

C. H. Lin ◽

S. L. Sass

Keyword(s):

Grain Boundaries ◽

Analytical Electron Microscopy ◽

Solute Segregation ◽

X Ray ◽

Periodic Arrays ◽

Analytical Electron ◽

Primary Dislocation ◽

Tilt Boundaries ◽

Polycrystalline Solids ◽

Twist Boundaries

The segregation of solute atoms to grain boundaries in polycrystalline solids can be responsible for embrittlement of the grain boundaries. Although Auger electron spectroscopy (AES) and analytical electron microscopy (AEM) have verified the occurrence of solute segregation to grain boundaries, there has been little experimental evidence concerning the distribution of the solute within the plane of the interface. Sickafus and Sass showed that Au segregation causes a change in the primary dislocation structure of small angle [001] twist boundaries in Fe. The bicrystal specimens used in their work, which contain periodic arrays of dislocations to which Au is segregated, provide an excellent opportunity to study the distribution of Au within the boundary by AEM.The thin film Fe-0.8 at% Au bicrystals (composition determined by Rutherford backscattering spectroscopy), ∼60 nm thick, containing [001] twist boundaries were prepared as described previously. The bicrystals were analyzed in a Vacuum Generators HB-501 AEM with a field emission electron source and a Link Analytical windowless x-ray detector.

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High-resolution electron microscopy of the atomic structure of some grain boundaries in Au

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143663 ◽

1986 ◽

Vol 44 ◽

pp. 414-415

Author(s):

W. Krakow ◽

D. A. Smith

Keyword(s):

Atomic Structure ◽

High Resolution Electron Microscopy ◽

Image Features ◽

Image Feature ◽

Resolution Electron ◽

Tilt Boundaries ◽

Processing Techniques ◽

Atom Position ◽

Structure Configuration

The successful determination of the atomic structure of [110] tilt boundaries in Au stems from the investigation of microscope performance at intermediate accelerating voltages (200 and 400kV) as well as a detailed understanding of how grain boundary image features depend on dynamical diffraction processes variation with specimen and beam orientations. This success is also facilitated by improving image quality by digital image processing techniques to the point where a structure image is obtained and each atom position is represented by a resolved image feature. Figure 1 shows an example of a low angle (∼10°) Σ = 129/[110] tilt boundary in a ∼250Å Au film, taken under tilted beam brightfield imaging conditions, to illustrate the steps necessary to obtain the atomic structure configuration from the image. The original image of Fig. 1a shows the regular arrangement of strain-field images associated with the cores of ½ [10] primary dislocations which are separated by ∼15Å.

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High-resolution microscopy of twin boundaries in gold

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126202 ◽

1987 ◽

Vol 45 ◽

pp. 260-261

Author(s):

William Krakow ◽

David A. Smith

Keyword(s):

High Resolution ◽

Specimen Preparation ◽

Gold Films ◽

Boundary Area ◽

Transmission Electron ◽

Recent Developments ◽

Tilt Boundaries ◽

High Resolution Microscopy ◽

Twist Boundaries

Recent developments in specimen preparation, imaging and image analysis together permit the experimental determination of the atomic structure of certain, simple grain boundaries in metals such as gold. Single crystal, ∼125Å thick, (110) oriented gold films are vapor deposited onto ∼3000Å of epitaxial silver on (110) oriented cut and polished rock salt substrates. Bicrystal gold films are then made by first removing the silver coated substrate and placing in contact two suitably misoriented pieces of the gold film on a gold grid. Controlled heating in a hot stage first produces twist boundaries which then migrate, so reducing the grain boundary area, to give mixed boundaries and finally tilt boundaries perpendicular to the foil. These specimens are well suited to investigation by high resolution transmission electron microscopy.

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ATOMIC STRUCTURE OF TILT BOUNDARIES IN Mo BICRYSTALS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1988507 ◽

1988 ◽

Vol 49 (C5) ◽

pp. C5-87-C5-97 ◽

Cited By ~ 1

Author(s):

J.-M. PENISSON

Keyword(s):

Atomic Structure ◽

Tilt Boundaries

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Hysteresis of the Grain-Boundary Mobility of the [10$$\overline{1}$$0] Tilt Boundaries in Zinc

Russian Metallurgy (Metally) ◽

10.1134/s0036029520100250 ◽

2020 ◽

Vol 2020 (10) ◽

pp. 1045-1049

Author(s):

V. G. Sursaeva

Keyword(s):

Grain Boundary ◽

Boundary Mobility ◽

Grain Boundary Mobility ◽

Tilt Boundaries

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Characterization of Tilt Boundaries by Ultra High Resolution Electron Microscopy

MRS Proceedings ◽

10.1557/proc-41-253 ◽

1984 ◽

Vol 41 ◽

Cited By ~ 2

Author(s):

W. Krakow ◽

J. T. Wetzel ◽

D. A. Smith ◽

G. Trafas

Keyword(s):

High Resolution ◽

Grain Boundary ◽

Structural Information ◽

Theoretical Work ◽

High Resolution Electron Microscopy ◽

Point Of View ◽

Experimental Point ◽

Structure Information ◽

Resolution Electron ◽

Tilt Boundaries

AbstractA high resolution electron microscope study of grain boundary structures in Au thin films has been undertaken from both a theoretical and experimental point of view. The criteria necessary to interpret images of tilt boundaries at the atomic level, which include electron optical and specimen effects, have been considered for both 200kV and the newer 400kV medium voltage microscopes. So far, the theoretical work has concentrated on two different [001] tilt bounda-ries where a resolution of 2.03Å is required to visualize bulk lattice structures on either side of the interface. Both a high angle boundary, (210) σ=5, and a low angle boundary, (910) σ=41, have been considered. Computational results using multislice dynamical diffraction and image simulations of relaxed bounda-ries viewed edge-on and with small amounts of beam and/or specimen inclina-tion have been obtained. It will be shown that some structural information concerning grain boundary dislocations can be observed at 200kV. However, many difficulties occur in the exact identification of the interface structure viewed experimentally for both [001] and [011] boundaries since the resolution required is near the performance limit of a 200kV microscope. The simulated results at 400kV indicate a considerable improvement will be realized in obtain-ing atomic structure information at the interface.

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