Scientists Discover a Strange Hidden State Inside Liquid Metal
Something very surprising that was thought to be too unexpected to even exist was discovered by Scientists inside liquid metal. Even when metal is as hot as it can be, completely melted and very hot indeed, some atoms don’t move at all. Such immobile atoms can trap the liquid and prevent it from freezing in the usual way, resulting in a peculiar form of matter.
Normally, scientists believe that when a material melts, all its atoms move freely. But new research shows this is not always true. Some atoms stay fixed in place, even inside a liquid. These stationary atoms have a strong effect on how the liquid later turns into a solid.
The discovery is important because solidification comes into play in many natural processes: how minerals grow, how ice forms, and how proteins fold. It is also highly valuable in industries such as pharmaceuticals , aviation, construction, and electronics, where the rate at which materials freeze needs to be controlled.
To study that sequence of events, a team of scientists at the University of Nottingham in England and the University of Ulm in Germany watched tiny droplets of molten metal cool down. They employed a powerful technique called transmission electron microscopy, which can be used by scientists to see individual atoms. The results appear in the journal ACS Nano.
The team studied metal nanoparticles made of platinum, gold, and palladium. These particles were placed on an extremely thin sheet of carbon called graphene. Graphene was used to heat the particles until they melted. As expected, most atoms began moving quickly. However, the scientists were surprised to see that some atoms stayed completely still.
Further study showed that these unmoving atoms were strongly attached to defects in the graphene surface. This bond was so strong that the atoms stayed fixed even at very high temperatures. By using the electron beam, the researchers could create more defects and control how many atoms became pinned in place.
The electron beam played a unique role as well. It behaved as both a wave, revealing the atoms to the scientists, and particles, delivering little pulses of force. These bursts might drive atoms to a new position or else fix them in place. This weirdness enables the scientists to uncover an entirely new phase of matter.
But when the metal was restrained by just a few atoms, it froze as expected into crystals. But when a lot of atoms were pinned, crystal formation halted altogether. At times, there was a circle of the fixed atoms surrounding the liquid metal. This so-called “atomic corral” imprisoned the liquid, preventing it from solidifying, despite dropping to a temperature far below its typical freezing point. For platinum, the liquid was also still unfrozen as cold as 350°C, more than 1,000 degrees below what has been predicted.
When the temperature dropped even further, the trapped liquid finally became solid, but not as a crystal. Instead, it turned into an unstable, disordered metal. If the corral was disturbed, the metal quickly snapped back into its normal crystalline form.
This discovery could change how scientists understand catalysts, especially platinum-based ones used worldwide. It may lead to better, longer-lasting, and even self-cleaning catalysts. For the first time, scientists have successfully “corralled” atoms, opening the door to new materials that behave like both liquids and solids at the same time.
