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Cryo-FIB and High-Vacuum Cryo-Transfer for Atom Probe Tomography Analysis of Organic Molecular Materials


EMSL Project ID
51336

Abstract

The morphology of mixed molecular solids impacts macroscopic properties of the material (e.g. conductivity). Our group has developed atom probe tomography (APT) analysis methods for organic small-molecule materials to study nanoscale morphology and chemical degradation. Inorganic APT samples are typically fabricated using a focused ion beam (FIB) lift-out and annular milling process; however, organic molecules are sensitive to ion and electron radiation, making it challenging to apply this same method when analyzing organic materials. Therefore, we have thus far used vacuum thermal evaporation (VTE) to deposit organic materials on a pre-formed needle-shaped substrate. While this sample preparation method has enabled valuable insights into structure-property relationships in organic molecular films, the types of materials to which it can apply is limited.

This work will develop damage-minimized FIB sample preparation methods for APT analysis of organic molecular materials. This development takes advantage of the unique EMSL facilities that combine a cryo-FIB and high-vacuum cryo-transfer to the Atom Probe. By optimizing and characterizing damage during sample preparation (e.g. through comparing the APT mass spectral signatures of FIB-prepared samples to pristine samples prepared on pre-formed needle-shaped tips), we will improve sample preparation techniques, enhancing the quality of data for materials analysis methods and widening the array of materials whose nanoscale morphology can be characterized with APT. This inquiry will expand the capabilities of EMSL for interface analysis and microstructural characterization of soft organic materials, and reveal relationships between the nanoscale structure of organic materials and their macroscopic properties.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2020-10-01
End Date
2022-09-30
Status
Closed

Team

Principal Investigator

Jeramy Zimmerman
Institution
Colorado School of Mines

Team Members

Andrew Proudian
Institution
Colorado School of Mines