Carbon Chemist

Tag: diamonds

  • Record-breaking diamond storage can save data for millions of years

    Record-breaking diamond storage can save data for millions of years

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    New Scientist. Science news and long reads from expert journalists, covering developments in science, technology, health and the environment on the website and the magazine.

    Diamonds can store data stably for long periods of time

    University of Science and Technology of China

    The famous marketing slogan about how a diamond is forever may only be a slight exaggeration for a diamond-based system capable of storing information for millions of years – and now researchers have created one with a record-breaking storage density of 1.85 terabytes per cubic centimetre.

    Previous techniques have also used laser pulses to encode data into diamonds, but the higher storage density means a diamond optical disc with the same volume as a standard Blu-ray could store approximately 100 terabytes of data – the equivalent of about 2000 Blu-rays – while lasting far longer than a typical Blu-ray’s lifetime of just a few decades.

    “Once the internal data storage structures are stabilised using our technology, diamond can achieve extraordinary longevity – data retention for millions of years at room temperature – without requiring any maintenance,” says Ya Wang at the University of Science and Technology of China in Hefei.

    Wang and his colleagues worked with small pieces of diamond only a few millimetres long, although they say future versions of the system could involve a diamond disc spinning at high speeds. Their method used ultrafast laser pulses to knock some of a diamond’s carbon atoms out of place, leaving behind empty spaces the size of single atoms that each exhibited a stable brightness level.

    By controlling the energy of the laser, the researchers could make multiple empty spaces at specific sites within the diamond, and the density of those spaces influenced each site’s overall brightness. “The number of empty spaces can be determined by looking at the brightness, which allows us to read the stored information,” says Wang.

    The team then stored images – including artist Henri Matisse’s colourful painting Cat with Red Fish and Eadweard Muybridge’s 1878 sequence of photos showing a rider on a galloping horse – by mapping the brightness of each pixel to the brightness levels of specific sites inside the diamond. The system saved this data with more than 99 per cent accuracy and completeness.

    This storage method isn’t yet commercially viable because it requires expensive lasers and high-speed fluorescence imaging cameras, along with other devices, says Wang. But he and his colleagues expect that their diamond-based system could eventually be miniaturised to fit within a space the size of a microwave oven.

    “In the short term, government agencies, research institutes and libraries focused on archiving and data preservation would likely be eager to adopt this technology,” he says.

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  • Mercury may have a layer of diamond beneath its grey surface

    Mercury may have a layer of diamond beneath its grey surface

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    Does Mercury have a sparkling secret?

    NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

    A thick layer of diamonds may be hidden hundreds of kilometres below the surface of Mercury, according to an experiment recreating early conditions on the solar system’s smallest planet.

    We already know that Mercury is rich in carbon, the element that makes up diamonds, thanks to observations by NASA’s Messenger orbiter, which revealed a surface covered in graphite.  This carbon is likely to be spread throughout the planet’s interior, where its exact form will depend on the temperature and pressure at each location.…

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  • Why supersonic, diamond-spewing volcanoes might be coming back to life

    Why supersonic, diamond-spewing volcanoes might be coming back to life

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    armand sarlangue **ONE-TIME USE ONLY** for Diamond Volcanoes feature armand sarlangue

    Twenty years ago, deep beneath Botswana’s Kalahari desert, Thomas Gernon found himself walking in what seemed like hell. The temperature soared as the sound of explosions echoed off the walls. “It was like a baptism of fire,” he says. It was his first trip into a kimberlite diamond mine.

    The place teemed with cameras and Gernon, now at the University of Southampton in the UK, had been warned of trouble should any gemstones be found – accidentally or otherwise – on his person. But he wasn’t here to find his fortune. He wanted an answer to one of Earth’s greatest mysteries.

    Diamonds are precious to many, but they hold a special place in the hearts of geologists. They were forged long ago in the fiery depths of Earth’s inaccessible mantle, brought to the surface by riding on supersonic jets of magma from bizarre volcanoes called kimberlites.

    We don’t know much about precisely how diamonds formed, but we do know they are like time capsules that can teach us the secrets of our planet’s distant past. And perhaps the biggest question of all is why the kimberlites that propelled them to the surface seem to have gone extinct millions of years ago.

    Now, almost two decades since that first visit to a diamond mine, Gernon and his fellow kimberlite detectives may finally have an all-encompassing model for how the volcanoes work, and with it a better understanding of their treasures. What’s more, this work has uncovered a tantalising prospect – that kimberlites might not be extinct after all.

    Diamonds, contrary…

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  • Supercomputers Crack the Code of Super-Diamond Synthesis

    Supercomputers Crack the Code of Super-Diamond Synthesis

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    Synthesis Pathways for BC8 “Super Diamond”

    Supercomputer simulations predicting the synthesis pathways for the elusive BC8 “super-diamond”, involving shock compressions of diamond precursor, inspire ongoing Discovery Science experiments at NIF. Credit: Mark Meamber/LLNL

    Researchers are on a quest to synthesize BC8, a carbon structure predicted to be tougher than diamond, using insights from advanced simulations and experimental efforts. This material, theoretically prevalent in the extreme pressures of exoplanets, remains a scientific mystery with promising applications in materials science.

    Diamond is the strongest material known. However, another form of carbon has been predicted to be even tougher than diamond. The challenge is how to create it on Earth.

    The eight-atom body-centered cubic (BC8) crystal is a distinct carbon phase: not diamond, but very similar. BC8 is predicted to be a stronger material, exhibiting a 30% greater resistance to compression than diamond. It is believed to be found in the center of carbon-rich exoplanets. If BC8 could be recovered under ambient conditions, it could be classified as a super-diamond.

    Theoretical Insights and Experimental Challenges

    This crystalline high-pressure phase of carbon is theoretically predicted to be the most stable phase of carbon under pressures surpassing 10 million atmospheres.

    “The BC8 phase of carbon at ambient conditions would be a new super-hard material that would likely be tougher than diamond,” said Ivan Oleynik, a physics professor at the University of South Florida (USF) and senior author of a paper recently published in The Journal of Physical Chemistry Letters.

    The Extraterrestrial Connection

    “Despite numerous efforts to synthesize this elusive carbon crystalline phase, including previous National Ignition Facility (NIF) campaigns, it has yet to be observed,” said Lawrence Livermore National Laboratory (LLNL) scientist Marius Millot, who also was involved in the research. “But we believe it may exist in carbon-rich exoplanets.”

    Recent astrophysical observations suggest the plausible presence of carbon-rich exoplanets. These celestial bodies, characterized by considerable mass, experience gigantic pressures reaching millions of atmospheres in their deep interiors.

    Understanding BC8’s Unique Properties

    “Consequently, the extreme conditions prevailing within these carbon-rich exoplanets may give rise to structural forms of carbon such as diamond and BC8,” Oleynik said. “Therefore, an in-depth understanding of the properties of the BC8 carbon phase becomes critical for the development of accurate interior models of these exoplanets.”

    BC8 is a high-pressure phase of both silicon and germanium that is recoverable to ambient conditions, and theory suggests that BC8 carbon also should be stable at ambient conditions. LLNL scientist and co-author Jon Eggert said the most important reason that diamond is so hard is that the tetrahedral shape of the four-nearest-neighbor atoms in the diamond structure perfectly matches the optimal configuration of the four valence electrons in column-14 elements in the periodic table (beginning with carbon, followed by silicon and germanium).

    The Path to Synthesizing BC8

    “The BC8 structure maintains this perfect tetrahedral nearest-neighbor shape, but without the cleavage planes found in the diamond structure,” Eggert said, agreeing with Oleynik that “the BC8 phase of carbon at ambient conditions would likely be much tougher than diamond.”

    Through multi-million atomic molecular-dynamics simulations on Frontier, the fastest exascale supercomputer in the world, the team uncovered the extreme metastability of diamond at very high pressures, significantly exceeding its range of thermodynamic stability. The key for the success was the development of very accurate machine-learning interatomic potential that describes interactions between individual atoms with unprecedented quantum accuracy in at a wide range of high-pressure and temperature conditions.

    “By efficiently implementing this potential on GPU-based (graphics processing unit) Frontier, we can now accurately simulate the time evolution of billions of carbon atoms under extreme conditions at experimental time and length scales,” Oleynik said. “We predicted that the post-diamond BC8 phase would be experimentally accessible only within a narrow high-pressure, high-temperature region of the carbon phase diagram.”

    Future Horizons in BC8 Research

    The significance is twofold. First, it elucidates the reasons behind the inability of previous experiments to synthesize and observe the elusive BC8 phase of carbon. This limitation arises from the fact that BC8 can only be synthesized within a very narrow range of pressures and temperatures. Additionally, the study predicts viable compression pathways to access this highly restricted domain where BC8 synthesis becomes achievable. Oleynik, Eggert, Millot and others are currently collaborating to explore these theoretical pathways using Discovery Science shot allocations on NIF.

    The team dreams of one day growing BC8 super-diamond in the laboratory, if only they can synthesize the phase and then recover a BC8 seed crystal back to ambient conditions.

    Reference: “Extreme Metastability of Diamond and its Transformation to the BC8 Post-Diamond Phase of Carbon” by Kien Nguyen-Cong, Jonathan T. Willman, Joseph M. Gonzalez, Ashley S. Williams, Anatoly B. Belonoshko, Stan G. Moore, Aidan P. Thompson, Mitchell A. Wood, Jon H. Eggert, Marius Millot, Luis A. Zepeda-Ruiz and Ivan I. Oleynik, 25 January 2024, The Journal of Physical Chemistry Letters.
    DOI: 10.1021/acs.jpclett.3c03044

    The first author of the paper, Kien Nguyen Cong, a former Ph.D. student with Oleynik, is now a postdoctoral researcher at LLNL. Coauthors are Jonathan Willman, Joseph Gonzalez and Ashley Williams at USF; Anatoly Belonoshko of the Swedish Royal Institute of Technology; Stan Moore, Aidan Thompson and Mitchell Wood at Sandia National Laboratories; and Luis Zepeda-Ruiz at LLNL. The work at USF, LLNL and Sandia is funded by the National Nuclear Security Administration.



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