# Synopsis: Atoms Snap into Focus

Researchers unveil the first chemically sensitive transmission electron microscope with single-atom resolution.

By measuring how a beam of electrons is transmitted through a thin sample, modern transmission electron microscopes (TEMs) can acquire images with a resolution of about $50$ picometers, sufficient to image individual atoms. When passing through the sample, electrons can lose an amount of energy that is characteristic of the specific element with which they interact. Energy-filtered TEM (EFTEM) analyzes the energies of such transmitted electrons to obtain chemical maps of the specimen. Unfortunately, EFTEM techniques have not yet been able to achieve atomic resolution as their resolving power is limited by imperfections in the electron lenses, called chromatic aberrations, which cause electrons with different energies to be focused on different planes.

Writing in Physical Review Letters, Knut Urban at the Forschungszentrum Jülich, Germany, and an international team of scientists have now shown how atomic resolution can be recovered in EFTEM. The authors employed newly developed achromatic electron optics and carried out a benchmark test, imaging a single crystal of silicon and selectively acquiring only those electrons that interacted with specific core-shell electrons of silicon. The achieved resolution was sufficient to visualize so-called silicon “dumbbells”: neighboring silicon atoms that pair up in certain planes of the crystal. The images showed that the centers of two atoms in a dumbbell are separated by only $1.35$ angstroms. The scheme should allow unambiguous identification of the chemical nature of individual atoms in a sample containing multiple elements. – Matteo Rini

More Features »

### Announcements

More Announcements »

Optics

Read More »

## Next Synopsis

Semiconductor Physics

Read More »

## Related Articles

Materials Science

### Synopsis: Golden Mystery Solved

A long-standing discrepancy between experiments and theory concerning the electronic properties of gold has now been resolved. Read More »

Fluid Dynamics

### Focus: Nanochannel Could Separate Mixed Fluids

Calculations show that capillary forces affecting a fluid mixture flowing through a nanochannel could be used to separate the mixture. Read More »

Materials Science

### Synopsis: Metamaterial Inverts the Hall Effect

A metamaterial that looks like chainmail has a Hall coefficient whose sign is flipped compared to the material it’s made from. Read More »