Scientists uncover a ‘new state’ of matter by which atoms can exist as each strong AND liquid on the identical time
Scientists have discovered a new state of matter that isn’t a solid, liquid, or gas.
Researchers call this new type of material a ‘corralled supercooled liquid’.
Atoms in a liquid are normally like people in a busy crowd, constantly jostling and pushing past one another.
However, scientists have now found a way to freeze some of these atoms in place, creating an immobile ‘corral’ that keeps the mobile liquid atoms trapped inside.
Once the liquid is trapped inside a ring, its behaviour becomes different to any known form of matter.
Corralled atoms can remain liquid even when they are cooled to well below their freezing points.
Platinum, for example, can be kept liquid at temperatures as low as 350°C (662°F), more than 1,000°C (1,800°F) colder than normal.
Co-author Professor Andrei Khlobystov, of the University of Nottingham, says: ‘Our achievement may herald a new form of matter combining characteristics of solids and liquids in the same material.’
Scientists have discovered a new state of matter that doesn’t behave like a solid, liquid, or gas. They call it a corralled supercooled liquid (illustrated)
With the exception of plasma, all of the natural states of matter are produced by how much the molecules and atoms in a material move.
When a substance changes between a liquid and a solid, the atoms transition from freely moving around each other to being held in a tight grid.
This moment of change is extremely important for industrial applications such as metal production and pharmacy because it determines how crystals form in the resulting solid.
However, since the atoms in a liquid are all moving so fast, scientists have found it very challenging to understand what is going on in that moment.
To learn more, researchers used an electron scanning microscope to look at how individual atoms behaved in tiny samples of molten metal.
Co-author Dr Christopher Leist, a researcher from Ulm University who performed these experiments, says: ‘We began by melting metal nanoparticles, such as platinum, gold, and palladium, deposited on an atomically thin support – graphene.
‘We used graphene as a sort of hob for this process to heat the particles, and as they melted, their atoms began to move rapidly, as expected.
‘However, to our surprise, we found that some atoms remained stationary.’
Scientists found that when they melted nanoparticles of metals like platinum and hold, some of the individual atoms appeared to become stuck in place (yellow) and remained stationary
By using blasts of electrons, the researchers were able to trap more of the metal atoms in place. Eventually, this created a complete ring of stationary atoms surrounding a droplet of molten metal (illustrated)
Dr Leist and his colleagues soon realised that these atoms were essentially getting stuck at atomic-scale ‘defects’ in the graphene hot-plate.
Using small, targeted blasts of electrons, the researchers were able to fix even more atoms in place.
Eventually, the researchers were able to create a full ring of stationary atoms that surrounded a liquid puddle of molten metal.
Importantly, these stationary atoms had a significant impact on the solidification process.
When there were just a few stationary atoms, crystals formed in the liquid sections and grew until the entire particle became solid.
But when there is a high number of stationary atoms, no crystals form at all, and the liquid cannot change into a solid.
This is what allowed the researchers to create corralled supercooled liquids inside rings of stationary atoms, and unlock an entirely new state of matter.
In their paper, published in ACS Nano, they found that corralled supercooled liquids continue to move like liquids even when they are many hundreds of degrees below their freezing point.
When the metal was trapped by a ring of stationary particles (top), it was able to stay liquid at temperatures up to 1,000°C (1,800°F) colder than its freezing point. Scientists believe this may be a new state of matter
And, when they do eventually solidify, they form highly unstable amorphous solids rather than their normal crystal structures.
In terms of structure, this makes them more similar to glass than to any normal piece of metal.
In the future, the researchers hope that new shapes of atomic corral could unlock new ways of using rare metals in industry.
Platinum, for example, is one of the most important metals for industrial catalysts, materials that make chemical reactions happen faster, around the world.
The researchers say that finding a way to coax this metal into a new state of matter could ‘change our understanding of how catalysts work’.
Co-author Dr Jesum Alves Fernandes, of the University of Nottingham, says: ‘This advancement may lead to the design of self-cleaning catalysts with improved activity and longevity.’
