Strained state of Ge(Si) islands on Si: Finite element calculations and comparison to convergent beam electron‐diffraction measurements

The technique of convergent-beam electron diffraction (CBED) has been established. However there is a distinct discrepancy concerning the CBED pattern symmetries associated with translation symmetries parallel to the incident beam direction: Buxton et al. assumed no detectable effects of translation components, while Goodman predicted no associated symmetries. In this report a procedure used by Gjønnes & Moodie1 to obtain dynamical extinction rules will be extended in order to derive the CBED pattern symmetries as well as the dynamical extinction rules.

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A library of convergent-beam electron diffraction patterns

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144826 ◽

1986 ◽

Vol 44 ◽

pp. 688-691

Author(s):

John F. Mansfield

Keyword(s):

Electron Diffraction ◽

Materials Science ◽

Convergent Beam Electron Diffraction ◽

Beam Electron ◽

Transmission Electron ◽

Yield Information ◽

Analytical Electron ◽

Diffraction Patterns ◽

Convergent Beam ◽

Electron Energy Loss

One of the most important advancements of the transmission electron microscopy (TEM) in recent years has been the development of the analytical electron microscope (AEM). The microanalytical capabilities of AEMs are based on the three major techniques that have been refined in the last decade or so, namely, Convergent Beam Electron Diffraction (CBED), X-ray Energy Dispersive Spectroscopy (XEDS) and Electron Energy Loss Spectroscopy (EELS). Each of these techniques can yield information on the specimen under study that is not obtainable by any other means. However, it is when they are used in concert that they are most powerful. The application of CBED in materials science is not restricted to microanalysis. However, this is the area where it is most frequently employed. It is used specifically to the identification of the lattice-type, point and space group of phases present within a sample. The addition of chemical/elemental information from XEDS or EELS spectra to the diffraction data usually allows unique identification of a phase.

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Convergent-beam electron diffraction at high spatial resolution

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130390 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1152-1153 ◽

Cited By ~ 1

Author(s):

J W Steeds

Keyword(s):

Electron Diffraction ◽

High Temperature Superconductors ◽

Bloch Wave ◽

Convergent Beam Electron Diffraction ◽

Beam Electron ◽

Energy Filtering ◽

Small Probe ◽

Transmission Electron ◽

Electron Microscopes ◽

Convergent Beam

That the techniques of convergent beam electron diffraction (CBED) are now widely practised is evident, both from the way in which they feature in the sale of new transmission electron microscopes (TEMs) and from the frequency with which the results appear in the literature: new phases of high temperature superconductors is a case in point. The arrival of a new generation of TEMs operating with coherent sources at 200-300kV opens up a number of new possibilities.First, there is the possibility of quantitative work of very high accuracy. The small probe will essentially eliminate thickness or orientation averaging and this, together with efficient energy filtering by a doubly-dispersive electron energy loss spectrometer, will yield results of unsurpassed quality. The Bloch wave formulation of electron diffraction has proved itself an effective and efficient method of interpreting the data. The treatment of absorption in these calculations has recently been improved with the result that <100> HOLZ polarity determinations can now be performed on III-V and II-VI semiconductors.

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Convergent Beam Electron Diffraction Zone Axis Pattern Map of Zirconium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136088 ◽

1990 ◽

Vol 48 (2) ◽

pp. 496-497

Author(s):

E. Silva ◽

R. Scozia

Keyword(s):

Electron Diffraction ◽

Convergent Beam Electron Diffraction ◽

Zone Axis ◽

Pole Piece ◽

Small Particles ◽

Present Communication ◽

Beam Electron ◽

Zero Layer ◽

Set Up ◽

Convergent Beam

The purpose in obtaining zone axis pattern map (zap map) from a given material is to provide a quick and reliable tool to identify cristaline phases, and crystallographic directions, even in small particles. Bend contours patterns and Kossel lines patterns maps from Zr single crystal in the [0001] direction have been presented previously. In the present communication convergent beam electron diffraction (CBED) zap map of Zr will be shown. CBED patterns were obtained using a Philips microscope model EM300, which was set up to carry out this technique. Convergent objective upper pole piece for STEM and some electronic modifications in the lens circuits were required, furthermore the microscope was carefully cleaned and it was operated at a vacuum eminently good.CBED patterns in the Zr zap map consist of zero layer disks, showing fine details within them which correspond to intersecting set of higher order Laue zone (HOLZ) deficiency lines.

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