With the help of powerful computer simulations, Brown University researchers were able to identify a material with the highest melting point compared to any other known substance.
In as study published in the journal Physical Review B (Rapid Communications), the researchers described the computations, showing that a material made up of just the right proportions of carbon, nitrogen and hafnium will have a melting point of over 7,460 degrees Fahrenheit or 4,400 kelvins. That's around two-thirds of the temperature of the sun's surface and 200 kelvins hotter than the highest melting point ever reported experimentally.
The previous experimental record-holder for the highest melting point is a material containing carbon, tantalum and hafnium. After identifying carbon, nitrogen and hafnium as the components of a material that would set a new record, the researchers are now keen on synthesizing the material to investigate if their findings will prove the same in the lab.
Axel van de Walle, a co-author for the study, explained that the advantage of beginning with computations is that it's not costly to try a lot of different combinations. Not to mention that if they didn't do so first in this research, they would be blindly trying out combinations in the lab.
For the study, the researchers made use of a computational technique which infers a material's melting point by simulating physical processes at the atomic level, adhering to the law of quantum mechanics. Specifically, the technique observed melting dynamics as they occurred, in 100 or so atom blocks at a time.
The technique is highly efficient but it requires massive computational resources. Thankfully, the researchers had at their disposal Brown's "Oscar" high-performance cluster of computers and the National Science Foundation's Extreme Science and Engineering Discovery Environment computer network.
"Melting point is a really difficult prediction problem compared to what has been done before," said van de Walle, adding that's what makes the study special.
Discovering the highest melting point possible has possible application in the development of high-performance materials, such as those used in heat shields and gas turbines. However, the researchers admit that whether the carbon-nitrogen-hafnium material will be useful is yet to be determined. That's something further research will answer.
The study received support from Brown University and the U.S. Office of Naval Research.
