Electron Diffraction
(PDF-4+ 2018, PDF-4/Minerals 2018, PDF-4/Organics 2018)


Often in materials characterization, diverse forms of diffraction are used to complement one another. Research scientists often use electron diffraction as a method for obtaining diffraction intensities from nano-scale quantities of a material when X-ray scattering is limited. Given the complimentary character of the two techniques, ICDD has developed various options and tools that enable users to specify a diffraction type (X-ray or electron) when using the PDF-4+ reference database and its search/match capabilities.

Recent Electron Diffraction Updates:

PDF Card

  • Added “Electron Diffraction” radio button to the PDF card with “1/d (nm-1)” and “d (nm)” options.

SAED Pattern

  • Added a slider to the Camera Length setting.
  • Added “1/d (nm-1)” and “d (nm)” options for display data.

EBSD Pattern

  • Added a slider to the Camera Length setting.
  • Added “1/d (nm-1)” and “d (nm)” options for display data.

Ring Pattern

  • Added a slider to the Camera Length setting.
  • Camera Length now defaults to 100 cm for electron diffraction.
  • Changed default electron diffraction energy from 100 keV to 200 keV.
  • Plot Size now defaults to 10 cm for electron diffraction.
  • Added “1/d (nm-1)” and “d (nm)” to tooltips if simulating using electron diffraction.
  • Added option to enter Crystallite Size in nanometers (nm).

1D Diffraction Pattern

  • Added “d (nm)” and “d (nm-1)” options to the x-axis preference.

SIeve+

  • The periodic table is now shown for selecting elements when doing an electron diffraction search in SIeve+ (as opposed to typing in the elements).
electron diffraction

Users' experimental spot pattern (white spots) and graphical overlay of ED simulation of phase match from PDF-4+ (red spots). (Each simulation is interactive allowing dynamic updates to patterns by simply adjusting parameters such as zone axes, camera length, and electron voltage.)

Auto-indexing of zone axis in electron diffraction spot patterns

In 2014, ICDD implement deed an ability to identify the zone axis in a users' electron spot pattern. This new tool extracts spot positions (hkl's) from the users' ED spot pattern, and performs automated indexing totermine the zone axis.

New in Release 2015: The d-spacings and intensities of identified spots can now be listed in table format after the scale is specified. The table can then be saved as a ASCII format file. The user may also import data and generate graphical overlays for comparisons between possible phase matches.

 

Fast Facts on ICDD's Electron Diffraction Capability

  • Spot indexing
  • ED simulations for 348,397 entries
  • ED based phase ID
  • Atomic & molecular visualization


Technical Bulletin:

electron diffraction technical bulletin

Publications & Presentations:

M&M 2016: "The Power of Electron Diffraction Phase Analysis and Pattern Simulations Using the ICDD® Powder Diffraction File™ (PDF-4+)" - A. Gindhart, T. Blanton, J.Blanton, S. Gates-Rector

Tools for Electron Diffraction Pattern Simulation for the Powder Diffraction File – J. Reid, D. Crane, J. Blanton, C. Crowder, S. Kabekkodu, and T. Fawcett

M&M 2015: "Electron Diffraction Phase Analysis and Pattern Simulations Using the ICDD Powder Diffraction File (PDF-4+)" – S. Gates, K. Zhong, T. Blanton, J. Blanton

Tutorials:

electron

ELECTRON DIFFRACTION

sieve

ELECTRON DIFFRACTION
SEARCH STRATEGIES