Have you ever seen an atom?

Have you ever seen an atom?

October 17, 2019 100 By Stanley Isaacs


Have you ever seen at atom? Seeing as everything is made of them, you have. But have you ever seen one on its own? Over time, microscopes have
become more and more powerful, allowing us to see deeper into
the world of the ultra-small. Traditional light microscopes can be
used to see things like these onion cells and the structures within them as they
divide, pulling apart their chromosomes. But scientists have come up with a whole host
of clever methods to observe far smaller things. Using beams of electrons instead of light, we can
generate detailed images of chromosomes themselves. Recently, groups of scientists
around the world are becoming able to see materials at the most
fundamental scale – the atomic. One group from the University of California in Los
Angeles have been getting up close and personal with nanoparticles of platinum,
just a few nanometres across. Each of the tiny dots you can see here
are actually individual platinum atoms. But researchers didn’t stop
at a two-dimensional picture. By imaging over 100 slices of the
nanoparticle at different angles then removing the
noise with a special filter, they were able to map the location
of almost every atom. The information was used to create
a three-dimensional reconstruction of the whole particle
in unprecedented detail. It may look blurry, but this particle is
estimated to contain over 27,000 atoms and so, like flies in a swarm,
they appear to merge together. Every so often, though, we see the platinum’s atomic
structure align, granting us a moment of clarity. This technique is being used to analyse tiny irregularities
in the structure of the particle called dislocations. Dislocations are subtle, like the misalignment of
the green and red layers of atoms in this particle. But nonetheless, they can significantly
change the properties of materials, with effects ranging from a change in the
efficiency of LEDs to the strength of metal alloys. Three-dimensional atomic-scale imaging
like this is bettering our understanding of the structure of materials on
this truly fundamental scale.