Scanning Electron Diffraction Attachment with Electron Energy Filtering

1969 ◽  
Vol 40 (3) ◽  
pp. 424-433 ◽  
Author(s):  
J. F. Graczyk ◽  
S. C. Moss
Author(s):  
L. F. Barden ◽  
J. Craig Gray

The advantages of scanning electron diffraction with electron energy filtering over conventional electron diffraction have been fairly widely described, and, more recently, the use of such systems in conjunction with transmission electron microscopes has been reported. By means of scanning diffraction, the electron intensities in a diffraction pattern may be measured and plotted directly on an XY recorder without the inaccuracy and inconvenience of the normal photographic-densitometric process; and the use of an energy filter to remove electrons that have suffered an energy loss allows direct measurement of the diffracted intensities of the elastically-scattered electrons. In this paper, we describe a Scanning Electron Diffraction Attachment (SEDA) with electrostatic energy filter that has been constructed for use with the AEI EM6 and EM8 series of electron microscopes.


2019 ◽  
Author(s):  
Amro Dodin ◽  
Brian F. Aull ◽  
Roderick R. Kunz ◽  
Adam Willard

This manuscript presents a theoretical model for determining the electron energy filtering properties of nanocomposite materials. Individual nanoparticles can serve as energy filters for tunneling electrons due their discretized energy levels. Nanomaterials comprised of many individual nanoparticles can in principle serve the same purpose, however, particle polydispersity can lead to an additional source of energetic broadening. We describe a simple theoretical model that includes the effects of discrete energy levels and inhomogeneous broadening. We use this model to identify the material parameters needed for effective energy filtering by quantum dot solids.


Nano Letters ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 8441-8446
Author(s):  
Amro Dodin ◽  
Brian Aull ◽  
Roderick R. Kunz ◽  
Adam P. Willard

2019 ◽  
Author(s):  
Amro Dodin ◽  
Brian F. Aull ◽  
Roderick R. Kunz ◽  
Adam Willard

This manuscript presents a theoretical model for determining the electron energy filtering properties of nanocomposite materials. Individual nanoparticles can serve as energy filters for tunneling electrons due their discretized energy levels. Nanomaterials comprised of many individual nanoparticles can in principle serve the same purpose, however, particle polydispersity can lead to an additional source of energetic broadening. We describe a simple theoretical model that includes the effects of discrete energy levels and inhomogeneous broadening. We use this model to identify the material parameters needed for effective energy filtering by quantum dot solids.


2006 ◽  
Vol 156 (3) ◽  
pp. 524-536 ◽  
Author(s):  
Koji Yonekura ◽  
Michael B. Braunfeld ◽  
Saori Maki-Yonekura ◽  
David A. Agard

Author(s):  
R. Høier ◽  
M.Y. Kim ◽  
J.M. Zuo ◽  
J.C.H. Spence ◽  
D. Shindo

There have been few studies of thermal diffuse scattering (TDS) by electron diffraction although this scattering is easily observed. The TDS intensity distribution is as a rule strongly anisotropic which can be ascribed to scattering from individual phonon modes. Results reported so far in the literature are all based on qualitative or semi-quantitative use of the observed intensity distributions. However, at present several new methods (energy filters, imaging plate, CCD, digitized film) are available to extract data for detailed quantitative interpretation. In the present work the Zeiss 912 Omega energy filtering microscope has been used, combined with the Fuji Imaging Plate and a low temperature specimen holder. This opens new possibilities both for the study of soft modes and other TDS phenomena related to phase transitions, and also static disorder and order-disorder effects. By comparison with synchrotron work on TDS , crystals may be very much smaller and count rates are much higher. However, multiple scattering and Kikuchi lines may complicate the interpretation unless thin samples are used.


Author(s):  
J W Steeds

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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