Dynamical Diffraction

Some Applications of the U. S. Steel MVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070461 ◽

1973 ◽

Vol 31 ◽

pp. 4-5

Author(s):

J. S. Lally ◽

L. E. Thomas ◽

R. M. Fisher

Keyword(s):

Electron Diffraction ◽

Debye Temperature ◽

Metals And Alloys ◽

Critical Voltage ◽

Dynamical Diffraction ◽

Phase Structures ◽

Structure Factors ◽

Local Bonding ◽

Diffraction Phenomenon ◽

Multi Phase

A variety of materials containing many different microstructures have been examined with the USS MVEM. Three topics have been selected to illustrate some of the more recent studies of diffraction phenomena and defect, grain and multi-phase structures of metals and minerals.(1) Critical Voltage Effects in Metals and Alloys - This many-beam dynamical diffraction phenomenon, in which some Bragg resonances vanish at certain accelerating voltages, Vc, depends sensitively on the spacing of diffracting planes, Debye temperature θD and structure factors. Vc values can be measured to ± 0.5% in the HVEM ana used to obtain improved extinction distances and θD values appropriate to electron diffraction, as well as to probe local bonding effects and composition variations in alloys.

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Bijvoet pair's intensity ratio: Convergence of kinematic and dynamical diffraction

Physical Review Materials ◽

10.1103/physrevmaterials.4.123401 ◽

2020 ◽

Vol 4 (12) ◽

Author(s):

Xian-Rong Huang ◽

Lahsen Assoufid ◽

Ru-Wen Peng ◽

Albert T. Macrander ◽

Thomas Gog ◽

...

Keyword(s):

Intensity Ratio ◽

Dynamical Diffraction

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Algorithms for determining the phase of RHEED oscillations

Journal of Applied Crystallography ◽

10.1107/s1600576715020415 ◽

2015 ◽

Vol 48 (6) ◽

pp. 1927-1934 ◽

Cited By ~ 5

Author(s):

Zbigniew Mitura ◽

Sergei L. Dudarev

Keyword(s):

Experimental Data ◽

Direct Method ◽

Incident Beam ◽

Diffraction Theory ◽

High Energy ◽

Angle Of Incidence ◽

High Energy Electron ◽

Dynamical Diffraction ◽

Glancing Angle ◽

Low Symmetry

Oscillations of reflection high-energy electron diffraction (RHEED) intensities are computed using dynamical diffraction theory. The phase of the oscillations is determined using two different approaches. In the first, direct, approach, the phase is determined by identifying the time needed to reach the second oscillation minimum. In the second approach, the phase is found using harmonic analysis. The two approaches are tested by applying them to oscillations simulated using dynamical diffraction theory. The phase of RHEED oscillations observed experimentally is also analysed. Experimental data on the variation of the phase as a function of the glancing angle of incidence, derived using the direct method, are compared with the values computed using both the direct and harmonic methods. For incident-beam azimuths corresponding to low-symmetry directions, both approaches produce similar results.

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