Prediction of holz pattern shifts in convergent beam diffraction

1987 ◽  
Vol 5 (4) ◽  
pp. 373-377 ◽  
Author(s):  
A. G. Jackson
Keyword(s):  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

Using the TEM Condenser Lens to Switch between Image and Diffraction Modes

2013 ◽  
Vol 21 (2) ◽  
pp. 40-40
Author(s):  
Lydia Rivaud
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Transmission Electron Microscope ◽  
Condenser Lens ◽  
Selected Area Diffraction Pattern ◽  
Transmission Electron ◽  
Set Up ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

Central to the operation of the transmission electron microscope (TEM) (when used with crystalline samples) is the ability to go back and forth between an image and a diffraction pattern. Although it is quite simple to go from the image to a convergent-beam diffraction pattern or from an image to a selected-area diffraction pattern (and back), I have found it useful to be able to go between image and diffraction pattern even more quickly. In the method described, once the microscope is set up, it is possible to go from image to diffraction pattern and back by turning just one knob. This makes many operations on the microscope much more convenient. It should be made clear that, in this method, neither the image nor the diffraction pattern is “ideal” (details below), but both are good enough for many necessary procedures.

On the role of the second-order derivative term in the calculation of convergent beam diffraction patterns

2017 ◽  
Vol 179 ◽  
pp. 73-80 ◽  
Author(s):  
S.C. Hillier ◽  
E.T. Robertson ◽  
G.D. Reid ◽  
R.D. Haynes ◽  
M.D. Robertson
Keyword(s):  
Second Order ◽  
Order Derivative ◽  
Derivative Term ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

Energy-filtered convergent-beam diffraction: examples and future prospects

1995 ◽  
Vol 59 (1-4) ◽  
pp. 1-13 ◽  
Author(s):  
P.A. Midgley ◽  
M. Saunders ◽  
R. Vincent ◽  
J.W. Steeds
Keyword(s):  
Future Prospects ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

The Suppression of Contamination in the Convergent-Beam Electron Diffraction Camera

1977 ◽  
Vol 32 (11) ◽  
pp. 1326-1327 ◽  
Author(s):  
W. C. T. Dowell ◽  
P. Goodman
Keyword(s):  
Electron Diffraction ◽  
Vapour Phase ◽  
Convergent Beam Electron Diffraction ◽  
Beam Electron ◽  
Specimen Temperature ◽  
Surface Migration ◽  
Before And After ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

Abstract It has been demonstrated that specimen contamination in convergent-beam diffraction operation can be prevented by maintaining the specimen temperature between -110 °C and -165 °C, without the use of especially high or clean vacuum conditions. At these temperatures, surface migration of molecules causing contamination is evidently inhibited. Precautions to prevent deposition from the vapour phase both before and after cooling are also required.

Microdiffraction and convergent-beam diffraction from surfaces

1989 ◽  
Vol 47 ◽  
pp. 526-527
Author(s):  
J. A. Eades
Keyword(s):  
Surface Characterization ◽  
Normal Incidence ◽  
Grazing Incidence ◽  
High Energy ◽  
Large Area ◽  
High Energy Electrons ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

Microdiffraction from surfaces at near grazing incidence is an important method of surface characterization. It is very much akin to RHEED (reflection high-energy electron diffraction) except that in RHEED a large area of sample (∼ 1 mm2) contributes to the diffraction. In this respect the relationship between RHEED and surface microdiffraction is analogous to that between selected-area diffraction and microdiffraction in transmission. In addition RHEED systems usually have no post-specimen lenses and therefore operate at a fixed camera length.Surface microdiffraction can contribute important information for the characterization of surfaces but there are some important factors that make it more complex than in the case of convergent-beam diffraction in transmission.At grazing incidence, even with high-energy electrons, refraction at the surface is important -whereas in transmission (at near-normal incidence) it may be neglected.

scholarly journals Combing electron diffraction techniques for structure solution

2014 ◽  
Vol 70 (a1) ◽  
pp. C369-C369
Author(s):  
Andrew Stewart
Keyword(s):  
Electron Diffraction ◽  
Electron Diffraction Data ◽  
Data Sets ◽  
Data Set ◽  
Space Group ◽  
X Ray ◽  
Structure Solution ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

The last few years have seen a revolution in the field of 3D electron diffraction or diffraction tomography. We have moved from only acquiring a few low index zone axis patterns to full tomographic data sets recording all accessible areas of reciprocal space. These new larger data sets have made it easier for structure solution techniques such as direct methods from the x-ray world to be applied to the electron diffraction data for structure solution. While structure solution with tomographic electron diffraction is non trivial when compared to the x-ray case it is significantly easier than it was a few years ago. Mugnaioli et al. We are now in a situation where the most difficult and time consuming step can be the assignment of the space group to a data set. Electron diffraction has many advantages over the x-ray case in terms of the manner in which we can manipulate the electron beam. This allows the collection to convergent beam diffraction (CBD) or large angle convergent beam diffraction (LACBED) patterns, via the recently developed technique by Beanland et al. These techniques can make the assignment of space group significantly easier affair, and the path to structure solution a lot smoother. We will present the combination of data from tomographic, selected area (SA) and nano-beam (NBD) datasets, with diffraction from tomographic LACBED experiments where using the strengths of each technique can be leveraged for a much quicker route to structure solution.

Convergent-Beam Diffraction in the Characterization of Crystalline Phases

1985 ◽  
Vol 62 ◽  
Author(s):  
J. A. Eades ◽  
M. J. Kaufman ◽  
H. L. Fraser
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Zone Axis ◽  
Crystalline Materials ◽  
Powerful Technique ◽  
Transmission Electron ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

ABSTRACTConvergent-beam diffraction in the transmission electron microscope is a powerful technique for the characterization of crystalline materials. Examples are presented to show the way in which convergent-beam zone-axis patterns can be used to determine: the unit cell; the symmetry; the strain of a crystal. The patterns are also recognizable and so can be used, like fingerprints, to identify phases.

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