Atomistic simulation of the effect of impurities on vacancy migration at the {4 1 0}/[0 0 1] tilt grain boundary of MgO

1999 ◽  
Vol 27 (2) ◽  
pp. 133-137 ◽  
Author(s):  
M. A. Khan ◽  
D. J. Harris ◽  
S. C. Parker
Keyword(s):  
Grain Boundary ◽  
Atomistic Simulation ◽  
Vacancy Migration ◽  
Effect Of Impurities ◽  
Tilt Grain Boundary

Atomistic simulation of shear-coupled motion of [1 1 0] symmetric tilt grain boundary in α-iron

2018 ◽  
Vol 148 ◽  
pp. 141-148 ◽  
Author(s):  
Jian Yin ◽  
Yi Wang ◽  
Xiaohan Yan ◽  
Huaiyu Hou ◽  
Jing Tao Wang
Keyword(s):  
Grain Boundary ◽  
Atomistic Simulation ◽  
Coupled Motion ◽  
Symmetric Tilt ◽  
Tilt Grain Boundary

Atomistic Simulation of Stress-Induced Grain Boundary Diffusion: For Tin-Whisker Problem

2012 ◽  
Vol 706-709 ◽  
pp. 1545-1549 ◽  
Author(s):  
Yoshitaka Umeno ◽  
Jun Negami
Keyword(s):  
Grain Boundary ◽  
Atomistic Simulation ◽  
Boundary Diffusion ◽  
Interatomic Potential ◽  
Grain Boundary Diffusion ◽  
Boundary Structure ◽  
Stress Effect ◽  
Whisker Formation ◽  
Tin Whisker ◽  
Effect Of Impurities

The problem of whisker formation in tin (Sn) wiring in small electronic devices has become an important issue with the requirement of lead-free wiring, because doping of Pb to reduce whisker formation cannot be applied. It is therefore urged to better understand stress migration in tin, which is suspected to play a key role in whisker growth. We aim to study grain boundary diffusion in tin by atomistic simulation. After constructing an efficient interatomic potential suitable for diffusion of atoms using the genetic algorithm (GA), we perform molecular dynamics (MD) simulation of grain boundary diffusion in Sn under stress. We find that the magnitude of stress effect on diffusion depends on the boundary structure. Moreover, we examine the effect of impurities on vacancy migration by ab initio calculation to find atom doping that has potential to suppress diffusion.

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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