Science never ceases to amaze us! Researchers at Carnegie Institution of Washington’s Geophysical Laboratory have been working on simple phase transaction for many years, and they have finally cooled liquids below their freezing point without changing their physical state. They have come up with a way to change a solid into liquid form without changing its temperature in a phenomenon known as a phase transition. This is often known as “reconstructive phase transition” which is hard to predict, but for the first time has been controlled under lab conditions.
The process can occur in many ‘strange’ substances throughout the universe and can help us to create objects and substances unthinkable at this time.
Shen, in a press release, said:
“Because reconstructive phase transitions are the most fundamental type, this research provides a brand new way for understanding how different materials change”
At Carnegie Institution of Washington’s Geophysical Laboratory, Shen and his team performed the experiment by using a piece of crystalline bismuth in a diamond anvil cell. The pressure and decomposition ranged from 32,000 atmospheric pressure to 12,000 atmospheric pressure. The temperature for conducting the experiment was kept at 216°C, which is well below the melting point of bismuth i.e. 271.52°C, which obviously means that bismuth will be in the solid state at this temperature.
When the researchers put the bismuth at 32000 atmospheric pressure, they started to decompress it. When the pressure reached 23000 atmospheric pressure, the bismuth changed its state from solid to liquid, though the temperature remained constant. Below 15000 atmospheric pressure, it started to recrystallize, changing itself back to solid state.
The reason why bismuth changed its state into liquid, often known as the “metastable liquid,” is that the chemical bonds of bismuth were not broken, but actually the bonds changed their orientation and length which resulted in the change in its physical state.
Researchers also found that this liquid state can maintain its state for several hours, as long as the pressure and other conditions remains the same. But if these conditions are disturbed, then this liquid will change into its crystalline solid state.
Moreover, according to Shen, metastable liquids are not like the stable liquid. They seem to follow the law of physics, that when you slosh around the liquid, it will remain as liquid-like, not just as it was unlike the stable liquids.
“Metastable liquids have found a little nook in the laws of physics where they can stay liquid-like – but like a spinning plate balancing on a stick, any perturbation, and the atoms zip back into a solid form”
To visualize the state of liquid, freeze the bowl of water at 100°C and then force the icy water in the bowl to change into liquid by applying pressure without the change in its temperature.
Scientists are now trying to come up with new inventions using the concept of reconstructive phase transition which can truly revolutionize the world of science as we know it.
The research has been published in Nature Communications.