On-line high resolution image analysis

1988 ◽  
Vol 46 ◽  
pp. 970-971
Author(s):  
F. Huang ◽  
J. P. Zhang ◽  
M. I. Buckett ◽  
L. D. Marks
Keyword(s):  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Image Simulation ◽  
Fully Integrated ◽  
Recursive Filtering ◽  
Practical Applications ◽  
Resolution Electron ◽  
On Line ◽  
Rate Processes ◽  
Set Up

A persistent practical problem in high resolution electron microscopy has been the diffulty to obtain careful, statistical comparisons between experimental and theoretical images. As a rule, practical applications of image simulation have involved either a direct comparison of calculated and experimental images, or a comparison of digitized images from a microdensitometer. Both of these pose substantial impediments to the final goal of HREM, namely R-factor measurements of the agreement between experimental and theoretical images.As a step beyond these approaches, we have recently finished bus-interfacing a framestore device to an Apollo 3000 workstation. The full set-up is shown in Figure 1. The framestore device, an IMAGING 151 set of boards, can perform all the standard video rate processes such as recursive filtering, as well as accumulating a 16 bit image. This device is fully integrated into the Apollo mini-computer, and is set up so that images can be directly transferred to disk within the SEMPER software system.

Combined Experimentaland Theoretical Determination of the Atomic Structure of the (310) Twin in NB

1991 ◽  
Vol 238 ◽  
Author(s):  
Geoffrey H. Campbells ◽  
Wayne E. King ◽  
Stephen M. Foiles ◽  
Peter Gumbsch ◽  
Manfred Rühle
Keyword(s):  
High Resolution ◽  
Theoretical Models ◽  
High Resolution Electron Microscopy ◽  
Interatomic Potentials ◽  
Image Simulation ◽  
Theoretical Determination ◽  
Atomic Structures ◽  
Resolution Electron ◽  
High Resolution Images

ABSTRACTA (310) twin boundary in Nb has been fabricated by diffusion bonding oriented single crystals and characterized using high resolution electron microscopy. Atomic structures for the boundary have been predicted using different interatomic potentials. Comparison of the theoretical models to the high resolution images has been performed through image simulation. On the basis of this comparison, one of the low energy structures predicted by theory can be ruled out.

What is the Future for Image Simulation?

1997 ◽  
Vol 3 (S2) ◽  
pp. 1139-1140
Author(s):  
D. Van Dyck
Keyword(s):  
High Resolution ◽  
Atomic Structure ◽  
Structural Information ◽  
High Resolution Electron Microscopy ◽  
Information Channel ◽  
Image Simulation ◽  
Phase Information ◽  
Indirect Approach ◽  
Resolution Electron ◽  
High Resolution Images

The ultimate goal of high resolution electron microscopy is to determine quantitatively the atomic structure of an object. In this respect the electron microscope can be considered as an information channel that carries this information from the object to the observer. High resolution images are then to be considered as data planes from which the structural information has to be extracted.However this structural information is usually hidden in the images and cannot easily be assessed. Therefore, a quantitative approach is required in which all steps in the imaging process are taken into account. Two main approaches have been followed so far in the literature: the indirect approach in which the images are simulated for various plausible trial structures of the object and compared with the experimental images, and the direct approach in which the lost phase information is retrieved using holographic techniques so as to “deblur” the effect of the microscope and to reveal directly the atomic structure of the object.

The Atomic Structure of Mosaïc Grain Boundary Dislocations in GaN Epitaxial Layers

1999 ◽  
Vol 589 ◽  
Author(s):  
V. Potin ◽  
G. Nouet ◽  
P. Ruterana ◽  
R.C. Pond
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Atomic Structure ◽  
High Resolution Electron Microscopy ◽  
Anisotropic Elasticity ◽  
Epitaxial Layers ◽  
Threading Dislocations ◽  
Image Simulation ◽  
Resolution Electron

AbstractThe studied GaN layers are made of mosaYc grains rotated around the c-axis by angles in the range 0-25°. Using high-resolution electron microscopy, anisotropic elasticity calculations and image simulation, we have analyzed the atomic structure of the edge threading dislocations. Here, we present an analysis of the Σ = 7 boundary using circuit mapping in order to define the Burgers vectors of the primary and secondary dislocations. The atomic structure of the primary ones was found to exhibit 5/7 and 8 atom cycles.

Modified multislice theory for calculating the energy-filtered inelastic images in REM and HREM

1989 ◽  
Vol 45 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Z. L. Wang
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Diffuse Scattering ◽  
Transmission Function ◽  
High Resolution Electron Microscopy ◽  
Image Simulation ◽  
Resolution Electron ◽  
Electron Intensity ◽  
Reflection Electron Microscopy ◽  
Dependent Potential

Inelastic plasmon diffuse scattering (PDS) is treated as an effective position-dependent potential perturbing the incident electron wavelength in a solid surface, resulting in an extra phase grating term in the slice transmission function. This potential is derived for the geometry of reflection electron microscopy (REM) and high-resolution electron microscopy (HREM). The energy-filtered inelastic images can be calculated following the routine image simulation procedures by using different slice transmission functions for the elastic and inelastic waves, by considering the 'transitions' of the elastic scattered electrons to the inelastic scattered electrons. It is predicted that the inelastic scattering could modify the electron intensity distribution at a surface. It is possible to take high-resolution energy-filtered inelastic images of crystals, the resolution of which is about the same as that taken from the elastic scattered electrons.

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