Atomistic Calculations and Hrtem Observations of an [001] Tilt Boundary in Rutile

1993 ◽  
Vol 319 ◽  
Author(s):  
W.-Y. Lee ◽  
P.D. Bristowe ◽  
I.G. Solorzano ◽  
J.B. Vandersande
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Atomic Structure ◽  
Tilt Boundary ◽  
Energy Structure ◽  
Image Simulation ◽  
Resolution Electron ◽  
Atomistic Calculations ◽  
High Resolution Electron Microscope ◽  
Electron Microscope Image

AbstractThe equilibrium atomic structure of the ∑=15 36.9° (210)[001] tilt boundary in rutile (TiO2) has been computed using an ionic shell model and compared to a high-resolution electron microscope image of the same boundary using image simulation. The lowest energy structure of the boundary is characterized by an in-plane translation of a/6[120] relative to the mirrorsymmetric CSL configuration in agreement with the electron microscope observations.

Interfacial structure and interfacial reactions at the MgO/Al2O3 interface

1991 ◽  
Vol 49 ◽  
pp. 696-697
Author(s):  
D. X. Li ◽  
P. Pirouz ◽  
A. H. Heuer ◽  
S. Yadavalli ◽  
C. P. Flynn
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Molecular Beam ◽  
Interfacial Structure ◽  
Cross Sectional ◽  
Resolution Electron ◽  
High Resolution Electron Microscope ◽  
Electron Microscope Image ◽  
Image Simulations ◽  
Standard Techniques

MgO films were deposited on the (sample A), (0001)Al2O3 (sample B), and the (sample C) planes of sapphire by Molecular Beam Epitaxy (MBE). Cross-sectional UREM specimens were prepared using standard techniques and examined in a top-entry JEOL 4000FX high resolution electron microscope. Image simulations were performed using the SHRLI programs developed by O'Keefe.

High Resolution Study of CoSi2/Si (111) Interfaces

1990 ◽  
Vol 183 ◽  
Author(s):  
A. Catana ◽  
Ping Lu ◽  
David J. Smith
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Section ◽  
Atomic Structure ◽  
Interface Bonding ◽  
Resolution Electron ◽  
High Resolution Electron Microscope ◽  
Image Simulations ◽  
Resolution Study

AbstractThe atomic structure of A- and B-type CoSi2/Si (111) interfaces has been investigated by observations of samples in cross-section using a 400 kV high-resolution electron microscope. The samples were prepared by UHV e–beam evaporation of Co layers followed by annealing at temperatures between 300°C and 500°C. Based upon image simulations for various interface bonding models we have found evidence for 7–fold Co coordination at the A–type CoSi2/Si interfaces and for 7– and 8–fold coordination at the B-type interfaces.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Computer-Controlled Hrem Alignment Using Automated Diffractogram Analysis

1990 ◽  
Vol 48 (1) ◽  
pp. 532-533
Author(s):  
G.Y. Fan ◽  
O.L. Krivanek
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
The Other ◽  
Full Information ◽  
Resolution Electron ◽  
Skilled Operator ◽  
Automatic Alignment ◽  
High Resolution Electron Microscope ◽  
Computer Controlled ◽  
Recorded Image

Full alignment of a high resolution electron microscope (HREM) requires five parameters to be optimized: the illumination angle (beam tilt) x and y, defocus, and astigmatism magnitude and orientation. Because neither voltage nor current centering lead to the correct illumination angle, all the adjustments must be done on the basis of observing contrast changes in a recorded image. The full alignment can be carried out by a computer which is connected to a suitable image pick-up device and is able to control the microscope, sometimes with greater precision and speed than even a skilled operator can achieve. Two approaches to computer-controlled (automatic) alignment have been investigated. The first is based on measuring the dependence of the overall contrast in the image of a thin amorphous specimen on the relevant parameters, the other on measuring the image shift. Here we report on our progress in developing a new method, which makes use of the full information contained in a computed diffractogram.

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