On the Investigation of the Structure of Amorphous Substances by Means of Electron Diffraction

1982 ◽  
Vol 37 (10) ◽  
pp. 1139-1146 ◽  
Author(s):  
Frieder Paasdie ◽  
Herbert Olbrich ◽  
Ute Schestag ◽  
Peter Lamparter ◽  
Siegfried Steeb

A “Scanning High Energy Electron Diffraction”-(SHEED-)apparatus is described with which the intensity curves of elastically scattered electrons are obtained within a few minutes. The elimination of the inelastic background is done by means of an electrostatic filter with an energy resolution of 104, which is only limited by the line width of the beam producing system. The intensity curves obtained experimentally are corrected for multiple scattering.The pair correlation functions of amorphous Germanium as obtained by electron and X-ray diffraction are compared. The electron diffraction curves agree well with the corresponding curves of other authors. The same stands for the curves obtained with X-rays. The differences between the curves obtained with electrons and X-rays are discussed.

1993 ◽  
Vol 312 ◽  
Author(s):  
A. H. Bensaoula ◽  
A. Freundlich ◽  
A. Bensaoula ◽  
V. Rossignol

AbstractPhosphorus exposed GaAs (100) surfaces during a Chemical Beam Epitaxy growth process are studied using in-situ Reflection High Energy Electron Diffraction and ex-situ High Resolution X-ray Diffraction. It is shown that the phosphorus exposure of a GaAs (100) surface in the 500 – 580 °C temperature range results in the formation of one GaP monolayer.


2000 ◽  
Vol 639 ◽  
Author(s):  
Yoshiki Saito ◽  
Nobuaki Teraguchi ◽  
Akira Suzuki ◽  
Tomohiro Yamaguchi ◽  
Tsutomu Araki ◽  
...  

ABSTRACTInN films with excellent surface morphology were grown by controlled the V/III ratio of InN epitaxal layer. It was found they were single crystal of InN films with wurtzite structure by X-ray diffraction (XRD) measurement and reflection high-energy electron diffraction (RHEED) observation. Hall mobility as high as 760 cm2/Vs was achieved for InN film grown at 550°C with 240 W of RF plasma power with a carrier density of 3.0×1019 cm−3 at room temperature. To our knowledge, this electron mobility is the highest value ever reported.


1989 ◽  
Vol 160 ◽  
Author(s):  
J. Mattson ◽  
M. B. Brodsky ◽  
J. Ketterson ◽  
H. You

AbstractWe report X-ray diffraction and in-situ RHEED( Reflection High Energy Electron Diffraction) measurements on Cr thin films deposited on LiF[001] single crystal substrates for thicknesses up to 300 nm and for substrate temperatures from 30 to 450°C. From these measurements we determine the range of deposition conditions necessary for epitaxial growth and the stress in these films as a function of film thickness.


Author(s):  
T. K. Chatterjee ◽  
J. A. Spadaro ◽  
R. W. Vook

Matricardi et al. have shown that high energy electron diffraction patterns of unstained and unfixed catalase may be obtained with a high voltage TEM using a hydration stage and that without such a stage TED patterns could not be obtained. They showed that such patterns were observed only when the water vapor pressure in the vicinity of the catalase was greater than 90 percent of the equilibrium value. They attributed their results to the destruction of the crystallinity of catalase when it is vacuum dried. Similar results using X-ray diffraction techniques have been reported. Matricardi et al. also noted effects due to radiation damage, whereby the number of reflections observed using the hydration stage decreased substantially with electron beam exposure. In the present preliminary report, it is shown that electron diffraction patterns can be obtained from unstained and unfixed catalase even when the crystals are exposed directly to the vacuum of the TEM but under such conditions whereby the electron beam intensity is reduced by up to approximately two orders of magnitude from that usually obtained in normal TED work on a TEM.


2020 ◽  
Vol 76 (3) ◽  
pp. 328-333
Author(s):  
Zbigniew Mitura

Azimuthal plots for RHEPD (reflection high-energy positron diffraction) and RHEED (reflection high-energy electron diffraction) were calculated using dynamical diffraction theory and then compared. It was assumed that RHEPD and RHEED azimuthal plots can be collected practically by recording the intensity while rotating the sample around the axis perpendicular to the surface (for the case of X-ray diffraction, such forms of data are called Renninger scans). It was found that RHEPD plots were similar to RHEED plots if they were compared at Bragg reflections of the same order. RHEPD plots can also be determined in the region of total external reflection and for such conditions multiple scattering effects turned out to be very weak. The findings for azimuthal plots are also discussed in the context of the formation mechanisms of Kikuchi patterns.


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