Dissociated Σ=27 boundaries in silicon

1988 ◽  
Vol 46 ◽  
pp. 624-625
Author(s):  
A. Garg ◽  
W.A.T. Clark ◽  
J.P. Hirth
Keyword(s):  
Electron Diffraction ◽  
Local Minimum ◽  
Boundary Energy ◽  
Coincidence Site Lattice ◽  
Boundary Plane ◽  
Low Energy ◽  
Theoretical Understanding ◽  
Site Lattice ◽  
Kikuchi Pattern ◽  
Analysis Techniques

In the last twenty years, a significant amount of work has been done in the theoretical understanding of grain boundaries. The various proposed grain boundary models suggest the existence of coincidence site lattice (CSL) boundaries at specific misorientations where a periodic structure representing a local minimum of energy exists between the two crystals. In general, the boundary energy depends not only upon the density of CSL sites but also upon the boundary plane, so that different facets of the same boundary have different energy. Here we describe TEM observations of the dissociation of a Σ=27 boundary in silicon in order to reduce its surface energy and attain a low energy configuration.The boundary was identified as near CSL Σ=27 {255} having a misorientation of (38.7±0.2)°/[011] by standard Kikuchi pattern, electron diffraction and trace analysis techniques. Although the boundary appeared planar, in the TEM it was found to be dissociated in some regions into a Σ=3 {111} and a Σ=9 {122} boundary, as shown in Fig. 1.

Characterization of an anomaly in the crystallographic orientation of plate-like carbides precipitated in a wrought Ni-base superalloy

2012 ◽  
Vol 45 (4) ◽  
pp. 719-725 ◽  
Author(s):  
H. W. Jeong ◽  
I. S. Kim ◽  
S. M. Seo ◽  
Y. S. Yoo ◽  
B. G. Choi ◽  
...  
Keyword(s):  
Orientation Relationship ◽  
Crystallographic Orientation ◽  
Boundary Energy ◽  
Coincidence Site Lattice ◽  
Elastic Strain Energy ◽  
Coincidence Site Lattice Boundary ◽  
Site Lattice ◽  
Cube Orientation ◽  
The Matrix ◽  
Lattice Boundary

Face-centred cubic Cr-rich carbide is known to precipitate in a face-centred cubic matrix with a cube–cube orientation relationship, thereby minimizing the elastic strain energy. In the present study, for the first time, the precipitation was observed of an abnormal Cr-rich carbide, which did not have the cube–cube orientation relationship in its face-centred cubic matrix. The abnormally oriented carbides nucleated and grew around random grain boundaries, and were observed to have a lamellar or plate-like morphology. The crystallographic orientation anomaly was characterized by measuring the tilt angles of the three crystal poles of the matrices, carbides and adjacent grains, using a transmission electron microscope to find the closest coincidence site lattice boundary. The carbides showed a slight deviation from a cube–cube orientation with adjacent grains and did not present any particular orientational relationship with the matrix. The deviation angles from coincidence site lattice boundaries between the matrices and carbides were smaller than those between matrices and adjacent grains. The abnormally oriented carbides appeared to nucleate on adjacent grains, and underwent a rotation within the matrix during the initial stage of growth to release the phase boundary energy between the carbides and the matrix.

Grain boundary in textured YBa2Cu3O7−δ superconductor

1991 ◽  
Vol 6 (12) ◽  
pp. 2507-2518 ◽  
Author(s):  
Yimei Zhu ◽  
H. Zhang ◽  
H. Wang ◽  
M. Suenaga
Keyword(s):  
Grain Boundaries ◽  
Coincidence Site Lattice ◽  
Large Angle ◽  
Low Energy ◽  
Site Lattice ◽  
Microscopy Technique ◽  
Rotation Axes ◽  
Transmission Electron ◽  
Complex Crystal Structure ◽  
Complex Crystal

The misorientations of over 200 pairs of adjacent grains separated by grain boundaries in textured YBa2Cu3O7−δ were measured using a transmission electron microscopy technique. The results indicate that there exist discrete preferred rotation angles and rotation axes. The existence of low-energy boundaries is inferred. The results are analyzed based on the Constrained Coincidence Site Lattice (CCSL) and O2-lattice theories and imply the applicability of such theories for the case of large-angle grain boundaries in a complex crystal structure such as YBa2Cu3O7−δ. The results of analysis also show that some boundaries are likely to be reduced in oxygen near the boundary to satisfy the constraint of the coincidence site lattice.

Low-Energy-Electron-Diffraction Structural Studies of (100) Cleavage Surfaces of In4Se3 Layered Crystals

2014 ◽  
Vol 59 (6) ◽  
pp. 612-621 ◽  
Author(s):  
P.V. Galiy ◽  
◽  
Ya.B. Losovyj ◽  
T.M. Nenchuk ◽  
I.R. Yarovets’ ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Low Energy ◽  
Energy Electron ◽  
Structural Studies ◽  
Low Energy Electron Diffraction ◽  
Layered Crystals ◽  
Low Energy Electron

Coincidence-Site-Lattice Twist Boundaries in Bicrystalline α-Fe2O3 Nanoblades

2014 ◽  
Vol 118 (11) ◽  
pp. 5796-5801 ◽  
Author(s):  
Yiqian Wang ◽  
Chao Wang ◽  
Lu Yuan ◽  
Rongsheng Cai ◽  
Xuehua Liu ◽  
...  
Keyword(s):  
Coincidence Site Lattice ◽  
Site Lattice ◽  
Twist Boundaries

The role of an energy-dependent inner potential in quantitative low-energy electron diffraction

2000 ◽  
Vol 458 (1-3) ◽  
pp. 155-161 ◽  
Author(s):  
S Walter ◽  
V Blum ◽  
L Hammer ◽  
S Müller ◽  
K Heinz ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Energy Dependent
Sign in / Sign up

Export Citation Format

Share Document