How To Turn Carbon Onions Into Oysters
How on earth can concentric carbon nanotubes turn into diamond after an intense bomabrdement of radiation? That’s the question that physicists have been struggling with since observing this phenomenon during the last decade or so.

Today, we get a full theoretical description of what’s going on thanks to a model built by Michael Zaiser and Stefan Chartier at the University of Edinburgh in the UK.
They say that the radiation bombardment knocks entire atoms out of the structure of nanotubes, causing the resulting defects to ricochet through the structure. This makes the structure bend and buckle, eventually forming into carbon spheres.
In fact, under intense radiation bombardment, this process turns multiwall nanotubes into carbon onions, ie concentric spheres.
As more atoms are knocked out of the structure, the spheres shrink, placing enormous streeses on the layers beneath. It is this stress that eventually causes diamond to form at the centre of the onion. “The resulting pressures are sufficient to explain the nucleation of diamond in irradiated carbon onions,” say Zaiser and Chartier
And when that happens, the carbon onion has clearly become a carbon oyster (of kinds)!
Ref: http://arxiv.org/abs/1009.4035: Irradiated Carbon Nanostructures as Nanoscopic Pressure Cells
Deep Dive
Uncategorized
Our best illustrations of 2022
Our artists’ thought-provoking, playful creations bring our stories to life, often saying more with an image than words ever could.
How CRISPR is making farmed animals bigger, stronger, and healthier
These gene-edited fish, pigs, and other animals could soon be on the menu.
The Download: the Saudi sci-fi megacity, and sleeping babies’ brains
10 Breakthrough Technologies 2023
Stay connected
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.