Matter takes many shapes, but most of us are familiar with the three basic states – solid, liquid, and gas. Now, for the first time, the researchers have discovered that it is possible for a matter to exist in two of these states at once.
Specifically, the metal potassium can be a solid and liquid simultaneously, if you treat it just like that. Simply apply extreme pressure and extreme temperature and presto! You have a chunk of potassium that is both solid and molten.
"It would be like holding a sponge filled with water that starts dripping out, except that the sponge is also made of water," the physicist Andreas Hermann of the University of Edinburgh told Adam Mann at National Geographic .
Potassium is pretty simple. It has a clean, crystalline lattice structure in its solid form.
We know, for example, that conducting metal sodium becomes an insulator at high pressure. Lithium is a superconductor at high pressure and low temperature
Previous experiments with potassium at high pressure showed that its atom is organized into a complex arrangement – five tubes of atoms in a square formation, four in the corners and one in the middle; and four chains of atoms bound between them.
When the heat is applied, the chains disappear; The researchers called this "chain-melting transition", thought to occur as a potassium chain transition from ordered to disordered state.
When trying and figuring out why this was happening, in the latest research, researchers used powerful computer simulations to observe the behavior of about 20,000 potassium atoms under extreme conditions.
When the pressure and temperature are high enough – about 2 to 4 Gigapascals – the potassium atom arranged themselves in interlinked chains and lattices.
The chemical interactions between the lattice atoms are strong, so they remain a ordered solid when the temperature is between 400 and 800 Kelvin. But meanwhile, the chains melt into a disordered, liquid state.
The team is calling this new state the "chain-melted phase", and I believe it may be able to exist across a range of materials, including sodium and bismuth,
"Potassium is one of the simplest metals we know, yet if you squeeze it, it forms very complex structures", Hermann said. 19659003] "We have shown that this unusual but stable state is part of solid and part liquid. Recreating this unusual state in other materials could have all kinds of applications."
The research should be published in PNAS .