Goodbye diamond. A new, even harder material is coming

Researchers at Lawrence Livermore National Laboratory (LLNL) and the University of South Florida (USF) have made significant progress in understanding a potential rival to diamond: an ultra-dense form of carbon: BC8, a "body-centered cubic structure of eight atoms".

The existence of BC8, which is considered to be a different phase of carbon, has been theorized for around 40 years, and scientists calculate that this material could surpass diamond in terms of hardness.

If it does exist, BC8 is likely to be found on carbon-rich exoplanets, and has a higher compressive strength and thermal conductivity than diamond.

Using the computing power of the Frontier supercomputer, the researchers simulated the behavior of billions of carbon atoms under extreme conditions.

The study, published in The Journal of Physical Chemistry Letters, suggests a possible way to create BC8.

"We predicted that the post-diamond BC8 phase would be experimentally accessible only in a narrow high-pressure, high-temperature region of the carbon phase diagram," explains USF's Ivan Oleynik in a press release from Lawrence Livermore National Laboratory.

The road to understanding BC8 has been difficult. Previous attempts offered tantalizing clues, but failed to confirm its existence. However, advances in computational modeling have allowed researchers to explore the metastability of diamond at extreme pressures more comprehensively.

The latest findings shed light on why previous attempts to find BC8 were unsuccessful. The structure of this super-diamond can only form under specific pressure and temperature conditions, which explains why it has not been detected until now.

The implications of BC8 go far beyond our planet. Understanding its properties could provide insights into the composition of carbon-rich exoplanets and improve models of the interior of these distant worlds.

It remains to be seen whether the new material will also replace diamond in the role it was given in a famous Hollywood film and eternalized by Marilyn Monroe: that of "women's best friend".