Unique cryo-transfer probe maps atoms


Rebecca Pool

Wednesday, April 19, 2017 - 20:15
Image: 'Cryo-Transfer' LEAP atom probe, manufactured by Cameca
Researchers from ETH Zürich, Switzerland, and UK-based Oxford University have succeeded in mapping volatile hydrogen atoms in metal using the first 'cryo-transfer' local electrode atom probe, known as LEAP.
Hydrogen inclusions in metal can severely affect material properties, making the metal more brittle.
To avoid failures in steel or other metals due to hydrogen embrittlement and cracks, researchers need to precisely locate the atoms of hydrogen.
Atom Probe Tomography (APT) has proven to be one of the best analytical techniques for identifying and determining the position of nearly every atom in three dimensions in almost any nanoscale material.
Nevertheless, the 3-D mapping of hydrogen atoms has remained a challenge, even with improved APT instrumentation, because hydrogen atoms are so mobile.
Given this, researchers at the University of Oxford, investigating the origins of hydrogen embrittlement, teamed up with the materials research team at ETH Zürich, which has developed a unique cryogenic transfer protocol for its LEAP Atom Probe.
Crucially, the protocol allows researchers to immobilize the highly diffusive hydrogen in the microstructure before APT analysis.
Hydrogen atoms (shown in red) within a 20x20x30 nm volume of a steel. Iron atoms are shown in purple with one fifth of atoms shown for visibility.
Together, the researchers succeeded in precisely identifying the mechanism by which a specific microstructure can trap individual hydrogen atoms within solid material using the ETH Zürich LEAP Atom Probe.
The researchers are confident the low-temperature APT protocol can be used for many other materials, including rubber or polymers, and even liquids.
CAMECA’s Atom Probe Tomography product line comprises two families: the LEAP 5000 (Local Electrode Atom Probe) family, which is said to provide the fastest, most sensitive 3-D imaging and analysis with nanoscale resolution across the widest range of applications (metals, oxides, ceramics, advanced energy storage materials, semiconductors and electronics, bio-minerals and geochemistry).
The newly launched EIKOS family offers accessibility to atom probe tomography with improved ease of use and a low cost of ownership for both general research and industrial applications.
Research is published in Science.
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