Most people know that the atoms in physical material exist in one of three states — either solid, liquid or gas. Recent research, however, suggests that may not exactly be true.
A team led by researchers from the University of Edinburgh reported in a recent study that they used computer simulations to study this new state of matter, which is referred to as a chain-melted state.
The scientists subjected virtual potassium to extreme temperatures and pressures, which caused it to take on the properties of both a liquid and a solid at the same time. In this state, most of the metal’s atoms formed a solid lattice structure, but some of them took on a fluid arrangement.
The researchers found that this chain-melted state persisted even when they dramatically changed the conditions within the simulation. This suggests it’s a stable type of matter, rather than a transition stage between solid and liquid.
The machine learning-powered simulation used by the Edinburgh and Xi’an Jiantong researchers to study potassium could be used to analyze how other elements react to extreme pressures and temperatures. This technique could help to improve our understanding of the properties of various materials and answer additional questions.
A Stunning Discovery
In real life, an object in this state would look and feel like a solid, but there would also be a liquid part that could leak out, the researchers said. If the material lost liquid, some of the solid atoms would change to replace it.
The extreme conditions that cause potassium to reach this chain-melted state exist in the Earth’s mantle. However, potassium is typically found bound with another material rather than in pure form.
In a previous study, the researchers showed that potassium, a highly reactive metal, had unique properties. They found exposing the potassium to high pressure caused it to form an abnormal crystal structure consisting of two interwoven lattices. Extreme pressure made the atoms change from their normally very simple structure to a highly complicated one.
In the recent study, the scientists used computer simulations to test how potassium atoms would behave under extreme pressures and temperatures. The use of machine learning enabled the team to study a high number of atoms — up to 20,000. When the researchers applied high temperatures to the virtual potassium atoms after they had already formed the two lattices, the atoms in one lattice remained strongly connected, while those in the other did not. In other words, the atoms in one lattice remained solid while those in the other became liquid.
The potassium then remained in the chain-melted state as the researchers raised the temperature by hundreds of degrees. This finding confirms that the state is stable rather than transitional — one that is a mixture of both solid and liquid interconnected at the atomic level.
The Edinburgh researchers carried out the study in collaboration with scientists from Xi’an Jiaotong University in China. The study was supported by the European Research Council and the Engineering and Physical Sciences Research Council and was published in the journal Proceedings of the National Academy of Sciences.
Other research has shown that other elements develop a structure of two intertwined lattices of atoms when exposed to extreme pressures. These elements, many of which are neighbors of potassium on the periodic table, may also be able to transform into a part-liquid, part-solid state. Researchers believe that more than half a dozen elements may be able to exist in this chain-melted state.
The results of this kind of research may one day even inform novel uses for materials, which will help pave the way for future advancements.
Written by Kayla Matthews, Productivity Bytes