ATOMIC STRUCTURE OF TILT BOUNDARIES IN Mo BICRYSTALS

1988 ◽  
Vol 49 (C5) ◽  
pp. C5-87-C5-97 ◽  
Author(s):  
J.-M. PENISSON
Keyword(s):  
Atomic Structure ◽  
Tilt Boundaries

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

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.

Atomic Structure and Property Correlation in Pulsed Laser Deposited High -Tc Films

1998 ◽  
Vol 526 ◽  
Author(s):  
R. Kalyanaraman ◽  
S. Oktyabrsky ◽  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundaries ◽  
Atomic Structure ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Structure And Property ◽  
Transmission Electron ◽  
Tilt Boundaries ◽  
Z Contrast

AbstractThe atomic structure of grain boundaries in pulsed laser deposited YBCO/MgO thin films have been studied using transmission electron microscopy. The films have perfect texturing with YBCO(001)//MgO(001), giving rise to low-angle [001] tilt boundaries from the grains with the c-axis normal to substrate surface. Low angle grain boundaries have been found to be aligned preferentially along (100) and (110) interface planes. The energy of (110) boundary planes described by an alternating array of [100] and [010] dislocation is found to be comparable to the energy of a (100) boundary. The existence of these split dislocations is shown to further reduce the theoretical current densities of these boundaries indicating that (110) boundaries carry less current as compared to (100) boundaries of the same misorientation angle. Further, Z-contrast transmission electron microscopy of a 42° asymmetric high-angle grain boundary of YBCO shows evidence for the existence of boundary fragments and a reduced atomic density along the boundary plane

scholarly journals Atomic Structure and Electronic State of Symmetric Tilt Boundaries in Palladium

2005 ◽  
Vol 69 (11) ◽  
pp. 1010-1015
Author(s):  
Takashi Mizuguchi ◽  
Naoki Takata ◽  
Ken-ichi Ikeda ◽  
Hideharu Nakashima
Keyword(s):  
Electronic State ◽  
Atomic Structure ◽  
Symmetric Tilt ◽  
Tilt Boundaries

High-resolution imaging of Σ=5 tilt boundaries in gold

1988 ◽  
Vol 46 ◽  
pp. 590-591
Author(s):  
F. Cosandey ◽  
S.-W. Chan ◽  
P. Stadelmann
Keyword(s):  
High Resolution ◽  
Grain Boundaries ◽  
Atomic Structure ◽  
Computational Models ◽  
Spherical Aberration ◽  
Computational Techniques ◽  
Recent Developments ◽  
Tilt Boundaries ◽  
High Resolution Images ◽  
Resolution Imaging

Until recently most of the information concerning the atomic structure of grain boundaries in metals has been obtained using molecular static and molecular dynamic computational techniques. With the recent developments of intermediate voltage microscope (300-400KV) this situation has changed and grain boundary atomic resolution is now possible for most metals. The purpose of this research is to examine the atomic structure of Σ=5 tilt boundaries in Au by high resolution microscopy and to compare the results to computational models.Thin film Au bicrystals containing Σ=5 (θ=36.5°±0.5) tilt grain boundaries were produced by epitaxial growth on NaCl bicrystalline substrates using a technique described in detail elsewhere. All high resolution images were obtained with a Philips 430 ST microscope using axial illumination and without objective aperture. All image simulations were obtained using the multislice formalism with EMS programs. All four {200} reflections from each crystal were used for the simulations with the following instrumental parameters; accelerating voltage V=300KV, spherical aberration constant Cs=1.1mm, defocus spread Δ=8nm and semi-angle beam divergence α=8mrad.

Grain Boundary Structure and Its Energy of Symmetric Tilt Boundary in Copper

2004 ◽  
Vol 467-470 ◽  
pp. 807-812 ◽  
Author(s):  
Naoki Takata ◽  
Kenichi Ikeda ◽  
Fusahito Yoshida ◽  
H. Nakashima ◽  
Hiroshi Abe
Keyword(s):  
Grain Boundary ◽  
Free Volume ◽  
Atomic Structure ◽  
Boundary Energy ◽  
Tilt Boundary ◽  
Grain Boundary Energy ◽  
Structural Units ◽  
Symmetric Tilt ◽  
Tilt Boundaries ◽  
Symmetric Tilt Boundary

In the present study, grain boundary energy and atomic structure of <110> symmetric tilt boundaries in copper were evaluated by molecular dynamics (MD) simulation. From the simulations, the grain boundary energy of <110> symmetric tilt boundaries depended on misorientation angle and there were large energy cusps at the misorientation angles which corresponded to (111) S 3 and (113) S 11 symmetric tilt boundaries. It was found that the atomic structure of each <110> symmetric tilt boundary was described by the combination of three kinds of structural units which consisted of (331) S 19, (111) S 3 and (113) S 11 symmetric tilt boundaries and two single crystal units which consisted of (110) S 1and (001) S 1 single crystals. From the the analysis of the excess free volume in each grain boundary, it was found that the energy of structural units depended on the excess free volume of the units and that the misorientation dependence of grain boundary energy agreed with that of the free volume in grain boundaries.

Diffusion, Migration and the Atomic Structure of some Grain Boundaries

1985 ◽  
Vol 57 ◽  
Author(s):  
W. Krakow ◽  
D. A. Smith
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Atomic Structure ◽  
Boundary Diffusion ◽  
Transmission Electron ◽  
Diffusion Migration ◽  
Tilt Boundaries ◽  
And Migration

AbstractThe atomic structure of representative tilt boundaries in gold has been determined by high resolution transmission electron microscopy. Characteristic and varying regions of decreased density and coordination have been identified and related to mechanisms of grain boundary diffusion and migration

scholarly journals Atomic structure and energy of triple junctions of tilt boundaries in nickel

2013 ◽  
Vol 3 (2) ◽  
pp. 72-75
Author(s):  
G. M. Poletaev ◽  
D. V. Dmitrienko ◽  
V. V. Diabdenkov ◽  
V. R. Mikrukov ◽  
M. D. Starostenkov
Keyword(s):  
Atomic Structure ◽  
Triple Junctions ◽  
Tilt Boundaries
Sign in / Sign up

Export Citation Format

Share Document