Discrimination of Aluminum from Silicon by Electron Crystallography with the JUNGFRAU Detector

• Main Authors: Erik Fröjdh, Julian T. C. Wennmacher, Przemyslaw Rzepka, Aldo Mozzanica, Sophie Redford, Bernd Schmitt, Jeroen A. van Bokhoven, Tim Gruene
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Crystals
• Subjects: charge-integrating detector; electron crystallography; aluminosilicates; discrimination of element types
• Online Access: https://www.mdpi.com/2073-4352/10/12/1148

The crystal structure of a chemical compound serves several purposes: its coordinates represent three-dimensional information about the connectivity between the atoms; it is the only technique that determines the absolute configuration of chiral molecules; it enables determining structure–function relations; and crystallographic data at atomic resolution distinguish between element types and serve as a confirmation of synthesis protocols. Here, we collected electron diffraction data from albite and from a Linde Type A (LTA) type zeolite. Both compounds are aluminosilicates with well-defined silicon and aluminum crystallographic sites. Data were recorded with the “adJUstiNg Gain detector FoR the Aramis User station” (JUNGFRAU detector) and we made use of its capability of energy discrimination to suppress noise. For both compounds, crystallographic refinement distinguishes correctly between silicon and aluminum, even though these elements have very similar electron scattering factors. These results highlight the quality of the electron diffraction data and the reliability of the models for chemical interpretation. Further development in this direction will provide enormous opportunities for structure–function studies by diffraction.