Atom Probe Tomography

Grain Size in Nanocrystalline Copper

This example demonstrates the multifaceted and diverse characterization facility that is ScopeM. We present metallic nano-printed pillars that were made by a cutting-edge automated technique developed in D-MATL’s Laboratory for Nanometallurgy group called electrohydrodynamic redox printing.

PhD candidate Maxence Menétrey first imaged the pillars with 465 nm wavelength photons (in argon gas) in Prof. Spolenak’s lab during the printing process (see figure, nozzle to pillar distance 7.5 μm), followed by characterizing them applying multiple electron and ion beams at increasing magnifications.

Enlarged view: Printing — Light microscopy of printing in action.

An electron beam accelerated to 3 kV (in high vacuum) was applied in a Scanning Electron Microscope,

Enlarged view: Printed_pillars — SEM of printed pillars.

followed by further interrogation & preparation using a 30 kV Focused Ion Beam

Enlarged view: Cross-section — SEM of FIB cross-section cut.

and imaged with 200 kV electrons in a Transmission Electron Microscope.

Enlarged view: Pillar — TEM of a pillar.

Finally, the makeup of the pillars were characterized in 3-dimensions by field ionization (in ultra high vacuum) with Atom Probe Tomography (each dot representing atomic positions and yellow surfaces highlighting regions of > 2 at.% H).

Enlarged view: Atom_map — APT atom map (scale in nm).

This combination of techniques - spanning over 9 orders of magnitude in spatial resolution - in a correlative fashion, enabled the quantification of modulations in microstructures – simply due to a difference in 6 V during printing – corresponding strength (mechanical properties) and the 3-dimensional chemical distributions (to < 0.1 at.% accuracy, see figure) within the sub-micrometer printed pillars.

Enlarged view: Elemental_composition — High compositional sensitivity as measured from APT.

References:

Reiser, A., et al., Multi-metal electrohydrodynamic redox 3D printing at the submicron scale. Nat. Commun. 10, 1853 (2019). external pageDOI: 10.1038/s41467-019-09827-1

Menetrey, M., et al., Targeted Additive Micromodulation of Grain Size in Nanocrystalline Copper Nanostructures by Electrohydrodynamic Redox 3D Printing. Small, vol. 18: no. 51, pp. 2205302, Weinheim: Wiley-VCH (2022). external pageDOI: 10.1002/smll.202205302