Image resolution in electron microscopy has traditionally been improved by increasing both the numerical aperture of the lens and the energy of the electron beam, which does for the microscope what light does for a camera or an optical microscope – illuminates the subject.
Previous records for resolution were achieved with an aberration-corrected lens and super-high beam energy – 300 kiloelectronvolts (keV) – to obtain sub-ångström resolution. Atomic bonds are generally between 1 and 2 ångströms (Å) long – an ångström is 0.1 nanometers – so sub-ångström resolution would allow one to easily see individual atoms. The Muller group was able to reach a resolution of 0.39 Å – a new world record – and at a lower, less damaging beam energy where resolution from the aberration corrected lenses alone was 0.98 Å.
Muller's group used the EMPAD and a technique known as ptychography: As the electron beam scans the sample, the detector collects both full-position and momentum distributions of the scattered electrons in overlapping steps. The image is reconstructed from the resulting 4-dimensional data set.
The group used a beam energy of just 80 keV so as not to destroy the MoS2. Despite the low beam energy, the resolution using EMPAD is so good, the microscope is able to detect with startling clarity a missing sulfur atom – "a defect in the lattice," Gruner said – in a 2-D material. "That's astounding to me," he said.
Ptychography on Wikipedia
The new resolution will be useful in nanotechnology.
(Score: 0, Troll) by Snotnose on Friday July 20 2018, @04:02AM
TheMightyBuzzard's dick?
Sorry dude, yours was the first name that came to mind.
When the dust settled America realized it was saved by a porn star.
(Score: 2) by KritonK on Friday July 20 2018, @08:22AM
I think I'll get one of those, to find all those pesky electron microscopes hiding in my bedroom, which I have been unable to catch.
(Score: 2) by opinionated_science on Friday July 20 2018, @10:25AM
or as the biologists say "cooking mark 1" ;-)
You should see lipid layers cook....
(Score: 2) by OrugTor on Friday July 20 2018, @02:08PM (2 children)
Stop using them.
(Score: 2) by takyon on Friday July 20 2018, @02:33PM
If we ever get sub-nanometer transistors, marketers can bring angstrom back.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by bob_super on Friday July 20 2018, @06:18PM
Dö ångströms måke yöu ångsty ör ångry ?