{"id":100773,"date":"2020-10-29T23:39:25","date_gmt":"2020-10-29T20:39:25","guid":{"rendered":"https:\/\/en.buradabiliyorum.com\/team-finds-path-to-nanodiamond-from-graphene\/"},"modified":"2020-10-29T23:39:25","modified_gmt":"2020-10-29T20:39:25","slug":"team-finds-path-to-nanodiamond-from-graphene","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/team-finds-path-to-nanodiamond-from-graphene\/","title":{"rendered":"#Team finds path to nanodiamond from graphene"},"content":{"rendered":"

“#Team finds path to nanodiamond from graphene<\/strong>”<\/p>\n

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\n Rice University researchers have expanded their theory on converting graphene into 2D diamond, or diamane. They have determined that a pinpoint of pressure can trigger connections between layers of graphene, rearranging the lattice into cubic diamond. Credit: Pavel Sorokin
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Marrying two layers of graphene is an easy route to the blissful formation of nanoscale diamond, but sometimes thicker is better.<\/p>\n


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While it may only take a bit of heat to turn a treated bilayer of the ultrathin material into a cubic lattice of diamane, a bit of pressure in just the right place can convert few-layer graphene as well.<\/p>\n

The otherwise chemically driven process is theoretically possible according to scientists at Rice University, who published their most recent thoughts on making high-quality diamane\u2014the 2-D form of diamond\u2014in the journal Small<\/i>.<\/p>\n

The research led by materials theorist Boris Yakobson and his colleagues at Rice’s Brown School of Engineering suggests a pinpoint of pressure on few-layer graphene, the atom-thin form of carbon known for its astonishing strength, can nucleate a surface chemical reaction with hydrogen or fluorine.<\/p>\n

From there, the diamondlike lattice should propagate throughout the material as atoms of hydrogen or fluorine alight on the top and bottom and covalently bind to the surfaces, prompting carbon-carbon connections between the layers.<\/p>\n

The pressure app<\/a>lied to that one spot\u2014as small as a few nanometers\u2014is entirely unnecessary for a bilayer but is needed and must be progressively stronger for thicker films, Yakobson said. Making synthetic diamond from bulk graphite at industrial scale requires about 10-15 gigapascals, or 725,000 pounds per square inch, of pressure.<\/p>\n

“Only at the nanoscale\u2014in this case, at nanometer thickness\u2014does it becomes possible for the surface chemistry alone to change the thermodynamics of the crystal, shifting the phase-change point from very high pressure to practically no pressure,” he said.<\/p>\n

Single-crystal diamond film for electronics is highly desirable. The material could be used as a hardened insulator or as a heat transducer for cooling nanoelectronics. It could be doped to serve as a wide band gap semiconductor in transistors, or as an element in optical applications.<\/p>\n

Yakobson and his colleagues developed a phase diagram in 2014 to show how diamane might be thermodynamically feasible. There’s still no easy way to make it, but the new work adds a critical component the earlier research lacked: a way to overcome the energetic barrier to nucleation that keeps the reaction in check.<\/p>\n

“So far only bilayer graphene has been reproducibly converted into diamane, but through sheer chemistry,” Yakobson said. “Combining it with a pinch of local pressure and the mechanochemistry it triggers seems like a promising path to be tried.”<\/p>\n

“In thicker films, the barrier rises quickly with the number of layers,” added co-author and former Rice postdoctoral associate Pavel Sorokin. “External pressure can reduce this barrier, but chemistry and pressure must play together to deliver a 2-D diamond.”<\/p>\n\n

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A new two-dimensional carbon allotrope: Semiconducting diamane film synthesized\n <\/p><\/div>\n

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\n More information:<\/strong>
\n Sergey V. Erohin et al, Nano\u2010Thermodynamics of Chemically Induced Graphene\u2013Diamond Transformation, Small<\/i> (2020). DOI: 10.1002\/smll.202004782<\/a><\/p>\n
\n Journal information:<\/strong>
\n Small<\/cite>
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\n Provided by
\n Rice University
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Citation<\/strong>:
\n Team finds path to nanodiamond from graphene (2020, October 29)
\n retrieved 29 October 2020
\n from https:\/\/phys.org\/news<\/a>\/2020-10-team-path-nanodiamond-graphene.html<\/p>\n

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