Quantitative Hrem Study of the Atomic Structure of the Σ(310)/[001] Symmetric Tilt Grain Boundary in Nb

1992 ◽  
Vol 295 ◽  
Author(s):  
Wayne E. King ◽  
Geoffrey H. Campbell
Keyword(s):  
Grain Boundary ◽  
Atomic Structure ◽  
Optimization Method ◽  
Interatomic Potentials ◽  
Cubic Metals ◽  
Symmetric Tilt ◽  
Resolution Electron ◽  
Least Squares Optimization ◽  
Tilt Grain Boundary ◽  
High Resolution Electron Micrographs

AbstractWe have used a non-linear least squares optimization method to deduce a model for the atomic structure of the Σ(310)/[001] symmetric tilt grain boundary in Nb from high resolution electron micrographs (HREM) of a bicrystal prepared by diffusion bonding. The resultant model is similar to, but differs in detail from a theoretical prediction based on interatomic potentials which included angular forces thought to be important in the prediction of defect structures in body centered cubic metals. Results validate this approach as a step towards making HREM a quantitative technique.

Atomic Structure of ZnO Σ13 [0001]/{134¯0} Symmetric Tilt Grain Boundary

2013 ◽  
Vol 97 (2) ◽  
pp. 617-621 ◽  
Author(s):  
Ji-Young Roh ◽  
Yukio Sato ◽  
Yuichi Ikuhara
Keyword(s):  
Grain Boundary ◽  
Atomic Structure ◽  
Symmetric Tilt ◽  
Tilt Grain Boundary

Atomic structure of the Σ5 (310)/[001] symmetric tilt grain boundary in molybdenum

1999 ◽  
Vol 47 (15-16) ◽  
pp. 3977-3985 ◽  
Author(s):  
G.H. Campbell ◽  
J. Belak ◽  
J.A. Moriarty
Keyword(s):  
Grain Boundary ◽  
Atomic Structure ◽  
Symmetric Tilt ◽  
Tilt Grain Boundary

Atomic structure of the σ5 (310)/[001] symmetric tilt grain boundary in tantalum

2000 ◽  
Vol 43 (7) ◽  
pp. 659-664 ◽  
Author(s):  
Geoffrey H Campbell ◽  
James Belak ◽  
John A Moriarty
Keyword(s):  
Grain Boundary ◽  
Atomic Structure ◽  
Symmetric Tilt ◽  
Tilt Grain Boundary

Σ =13 tilt grain boundary in silicon bicrystal

1990 ◽  
Vol 48 (4) ◽  
pp. 562-563
Author(s):  
M.J. Kim ◽  
Y.L. Chen ◽  
R.W. Carpenter ◽  
J.C. Barry ◽  
G.H. Schwuttke
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Rotation Axis ◽  
Czochralski Method ◽  
High Resolution Electron Microscopy ◽  
Image Simulation ◽  
Simulation Techniques ◽  
Resolution Electron ◽  
The Common ◽  
Tilt Grain Boundary

The structure of grain boundaries (GBs) in metals, semiconductors and ceramics is of considerable interest because of their influence on physical properties. Progress in understanding the structure of grain boundaries at the atomic level has been made by high resolution electron microscopy (HREM) . In the present study, a Σ=13, (510) <001>-tilt grain boundary in silicon was characterized by HREM in conjunction with digital image processing and computer image simulation techniques.The bicrystals were grown from the melt by the Czochralski method, using preoriented seeds. Specimens for TEM observations were cut from the bicrystals perpendicular to the common rotation axis of pure tilt grain boundary, and were mechanically dimpled and then ion-milled to electron transparency. The degree of misorientation between the common <001> axis of the bicrystal was measured by CBED in a Philips EM 400ST/FEG: it was found to be less than 1 mrad. HREM was performed at 200 kV in an ISI-002B and at 400 kv in a JEM-4000EX.

Structural Transformation of a Germanium Σ=13 (510) [001] Tilt Grain Boundary under the Electron Beam

1990 ◽  
Vol 48 (1) ◽  
pp. 52-53 ◽  
Author(s):  
Jean-Luc Rouvière ◽  
Alain Bourret
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Structural Transformation ◽  
Mirror Symmetry ◽  
High Resolution Electron Microscopy ◽  
Structural Transformations ◽  
Covalent Bonds ◽  
Resolution Electron ◽  
Tilt Grain Boundary

The possible structural transformations during the sample preparations and the sample observations are important issues in electron microscopy. Several publications of High Resolution Electron Microscopy (HREM) have reported that structural transformations and evaporation of the thin parts of a specimen could happen in the microscope. Diffusion and preferential etchings could also occur during the sample preparation.Here we report a structural transformation of a germanium Σ=13 (510) [001] tilt grain boundary that occurred in a medium-voltage electron microscopy (JEOL 400KV).Among the different (001) tilt grain boundaries whose atomic structures were entirely determined by High Resolution Electron Microscopy (Σ = 5(310), Σ = 13 (320), Σ = 13 (510), Σ = 65 (1130), Σ = 25 (710) and Σ = 41 (910), the Σ = 13 (510) interface is the most interesting. It exhibits two kinds of structures. One of them, the M-structure, has tetracoordinated covalent bonds and is periodic (fig. 1). The other, the U-structure, is also tetracoordinated but is not strictly periodic (fig. 2). It is composed of a periodically repeated constant part that separates variable cores where some atoms can have several stable positions. The M-structure has a mirror glide symmetry. At Scherzer defocus, its HREM images have characteristic groups of three big white dots that are distributed on alternatively facing right and left arcs (fig. 1). The (001) projection of the U-structure has an apparent mirror symmetry, the portions of good coincidence zones (“perfect crystal structure”) regularly separate the variable cores regions (fig. 2).

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