Convergent-Beam Diffraction in the Characterization of Crystalline Phases

MRS Proceedings ◽

10.1557/proc-62-143 ◽

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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One of my Failures: Diffraction in the TEM

Microscopy Today ◽

10.1017/s1551929510001252 ◽

2011 ◽

Vol 19 (1) ◽

pp. 72-72 ◽

Cited By ~ 1

Author(s):

Alwyn Eades

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Standard Method ◽

Transmission Electron ◽

Diffraction Patterns ◽

Convergent Beam ◽

Beam Diffraction ◽

Convergent Beam Diffraction

There are two principal techniques for obtaining diffraction patterns in the transmission electron microscope (TEM). They are selected-area diffraction (SAD) and convergent-beam diffraction (CBED). CBED is quicker and easier to use, and it provides a much richer characterization of the sample. Thus, it is clear that CBED should be used in the vast majority of cases. It should be the diffraction technique that students learn first, and students should be taught to consider it the standard method of doing diffraction in the TEM.

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

Microscopy Today ◽

10.1017/s1551929513000072 ◽

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.

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convergent-beam diffraction from surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125208 ◽

1987 ◽

Vol 45 ◽

pp. 30-33

Author(s):

J. A. Eades ◽

A. E. Smith ◽

D. F. Lynch

Keyword(s):

Reciprocal Lattice ◽

Three Dimensional ◽

Grazing Incidence ◽

Three Dimensions ◽

Plane Figure ◽

Transmission Electron ◽

Convergent Beam ◽

Beam Patterns ◽

Beam Diffraction

It is quite simple (in the transmission electron microscope) to obtain convergent-beam patterns from the surface of a bulk crystal. The beam is focussed onto the surface at near grazing incidence (figure 1) and if the surface is flat the appropriate pattern is obtained in the diffraction plane (figure 2). Such patterns are potentially valuable for the characterization of surfaces just as normal convergent-beam patterns are valuable for the characterization of crystals.There are, however, several important ways in which reflection diffraction from surfaces differs from the more familiar electron diffraction in transmission.GeometryIn reflection diffraction, because of the surface, it is not possible to describe the specimen as periodic in three dimensions, nor is it possible to associate diffraction with a conventional three-dimensional reciprocal lattice.

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Measurement of lattice parameter at the nanometer scale using convergent-beam microdiffraction from a thermal emission source

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100149283 ◽

1993 ◽

Vol 51 ◽

pp. 690-691

Author(s):

W. T. Pike

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Thermal Emission ◽

Lattice Parameter ◽

Scanning Transmission Electron Microscope ◽

Emission Source ◽

Device Structure ◽

Transmission Electron ◽

Scanning Transmission ◽

Convergent Beam

With the advent of crystal growth techniques which enable device structure control at the atomic level has arrived a need to determine the crystal structure at a commensurate scale. In particular, in epitaxial lattice mismatched multilayers, it is of prime importance to know the lattice parameter, and hence strain, in individual layers in order to explain the novel electronic behavior of such structures. In this work higher order Laue zone (holz) lines in the convergent beam microdiffraction patterns from a thermal emission transmission electron microscope (TEM) have been used to measure lattice parameters to an accuracy of a few parts in a thousand from nanometer areas of material.Although the use of CBM to measure strain using a dedicated field emission scanning transmission electron microscope has already been demonstrated, the recording of the diffraction pattern at the required resolution involves specialized instrumentation. In this work, a Topcon 002B TEM with a thermal emission source with condenser-objective (CO) electron optics is used.

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Characterization of Li-rich layered oxides by using transmission electron microscope

Green Energy & Environment ◽

10.1016/j.gee.2017.05.005 ◽

2017 ◽

Vol 2 (3) ◽

pp. 174-185 ◽

Cited By ~ 5

Author(s):

Hu Zhao ◽

Bao Qiu ◽

Haocheng Guo ◽

Kai Jia ◽

Zhaoping Liu ◽

...

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Layered Oxides ◽

Transmission Electron

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Characterization of JEOL 3000f TEM Equipped for Electron Holography

Microscopy and Microanalysis ◽

10.1017/s1431927600033638 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 228-229

Author(s):

M. A. Schofield ◽

Y. Zhu

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Design Of Experiment ◽

Electron Holography ◽

Fringe Spacing ◽

Interference Fringes ◽

Transmission Electron ◽

Careful Design

Quantitative off-axis electron holography in a transmission electron microscope (TEM) requires careful design of experiment specific to instrumental characteristics. For example, the spatial resolution desired for a particular holography experiment imposes requirements on the spacing of the interference fringes to be recorded. This fringe spacing depends upon the geometric configuration of the TEM/electron biprism system, which is experimentally fixed, but also upon the voltage applied to the biprism wire of the holography unit, which is experimentally adjustable. Hence, knowledge of the holographic interference fringe spacing as a function of applied voltage to the electron biprism is essential to the design of a specific holography experiment. Furthermore, additional instrumental parameters, such as the coherence and virtual size of the electron source, for example, affect the quality of recorded holograms through their effect on the contrast of the holographic fringes.

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