The Laplace Project: An integrated suite for preparing and transferring atom probe samples under cryogenic and UHV conditions

PLoS One. 2018 Dec 21;13(12):e0209211. doi: 10.1371/journal.pone.0209211. eCollection 2018.

Abstract

We present sample transfer instrumentation and integrated protocols for the preparation and atom probe characterization of environmentally-sensitive materials. Ultra-high vacuum cryogenic suitcases allow specimen transfer between preparation, processing and several imaging platforms without exposure to atmospheric contamination. For expedient transfers, we installed a fast-docking station equipped with a cryogenic pump upon three systems; two atom probes, a scanning electron microscope / Xe-plasma focused ion beam and a N2-atmosphere glovebox. We also installed a plasma FIB with a solid-state cooling stage to reduce beam damage and contamination, through reducing chemical activity and with the cryogenic components as passive cryogenic traps. We demonstrate the efficacy of the new laboratory protocols by the successful preparation and transfer of two highly contamination- and temperature-sensitive samples-water and ice. Analysing pure magnesium atom probe data, we show that surface oxidation can be effectively suppressed using an entirely cryogenic protocol (during specimen preparation and during transfer). Starting with the cryogenically-cooled plasma FIB, we also prepared and transferred frozen ice samples while avoiding significant melting or sublimation, suggesting that we may be able to measure the nanostructure of other normally-liquid or soft materials. Isolated cryogenic protocols within the N2 glove box demonstrate the absence of ice condensation suggesting that environmental control can commence from fabrication until atom probe analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cold Temperature
  • Ice
  • Materials Science / instrumentation
  • Materials Science / methods*
  • Nanostructures / chemistry
  • Tomography / instrumentation
  • Tomography / methods
  • Vacuum
  • Water / chemistry

Substances

  • Ice
  • Water

Grants and funding

The acquisition, development and maintenance for the various machines were supported in part by Germany’s Bundesministerium für Bildung und Forschung funding the UGSLIT and Laplace projects. KAKR is funded by Volkswagen Stifftung through the Experiment! program. YC is funded by a Chinese Scholarship Council scholarship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.