Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Diamond film possible without the pressure: Rice University, Russian researchers lay out rules for ultrathin 'diamane'

The phase diagram developed by scientists at Rice University and in Moscow describes the conditions necessary for the chemical creation of thin films of diamond from stacks of single-atomic-layer graphene.Credit: Pavel Sorokin/Technological Institute for Superhard and Novel Carbon Materials
The phase diagram developed by scientists at Rice University and in Moscow describes the conditions necessary for the chemical creation of thin films of diamond from stacks of single-atomic-layer graphene.

Credit: Pavel Sorokin/Technological Institute for Superhard and Novel Carbon Materials

Abstract:
Perfect sheets of diamond a few atoms thick appear to be possible even without the big squeeze that makes natural gems.

Diamond film possible without the pressure: Rice University, Russian researchers lay out rules for ultrathin 'diamane'

Houston, TX | Posted on February 3rd, 2014

Scientists have speculated about it and a few labs have even seen signs of what they call diamane, an extremely thin film of diamond that has all of diamond's superior semiconducting and thermal properties.

Now researchers at Rice University and in Russia have calculated a "phase diagram" for the creation of diamane. The diagram is a road map. It lays out the conditions - temperature, pressure and other factors - that would be necessary to turn stacked sheets of graphene into a flawless diamond lattice.

In the process, the researchers determined diamane could be made completely chemically, with no pressure at all, under some circumstances.

The team led by Rice theoretical physicist Boris Yakobson and Pavel Sorokin, a former postdoctoral associate at Rice and now a senior researcher at the Technological Institute for Superhard and Novel Carbon Materials in Moscow, reported results in the American Chemical Society journal Nano Letters.

"Diamanes have a wide potential range of application," Sorokin said. "They can be applied as very thin, dielectric hard films in nanocapacitors or mechanically stiff, nanothick elements in nanoelectronics. Also, diamanes have potential for application in nano-optics.

"The possibility of obtaining such a quasi-two-dimensional object is intriguing, but available experimental data prevents the expectation of its fabrication using traditional methods. However, the 'bottom-up' approach proposed by Richard Feynman allows the fabrication of diamanes from smaller objects, such as graphene."

The researchers built computer models to simulate the forces applied by every atom involved in the process. That includes the graphene, the single-atom-thick form of carbon and one of the strongest substances in the universe, as well as the hydrogen (or, alternately, a halogen) that promotes the reaction.

Conditions, they learned, need to be just right for a short stack of graphene pancakes to collapse into a diamond matrix - or vice versa - via chemistry.

"A phase diagram shows you which phase dominates the ground state for each pressure and temperature," Yakobson said. "In the case of diamane, the diagram is unusual because the result also depends on thickness, the number of layers of graphene. So we have a new parameter."

Hydrogen isn't the only possible catalyst, he said, but it's the one they used in their calculations. "When the hydrogen attacks, it takes one electron from a carbon atom in graphene. As a result, a bond is broken and another electron is left hanging on the other side of the graphene layer. It's now free to connect to a carbon atom on the adjacent sheet with little or no pressure.

"If you have several layers, you get a domino effect, where hydrogen starts a reaction on top and it propagates through the bonded carbon system," he said. "Once it zips all the way through, the phase transition is complete and the crystal structure is that of diamond."

Yakobson said the paper doesn't cover a possible deal-breaker. "The conversion from one phase to another starts from a small seed, a nucleation site, and in this process there's always what is called a nucleation barrier. We don't calculate that here." He said carbon normally prefers to be graphite (the bulk form of carbon used as pencil lead) rather than diamond, but a high nucleation barrier prevents diamond from making the transition.

"Thermodynamically, an existing diamond should become graphite, but it doesn't happen for exactly this reason," Yakobson said. "So sometimes it's a good thing. But if we want to make flat diamond, we need to find ways to circumvent this barrier."

He said the manufacture of synthetic diamond, which was first reliably made in the 1950s, requires very high pressures of about 725,000 pounds per square inch. Manufactured diamonds are used in hardened tools for cutting, as abrasives and even as high-quality gemstones grown via techniques that simulate the temperatures and pressures found deep in Earth, where natural diamond is forged.

Diamond films are also routinely made via chemical vapor deposition, "but they're always very poor quality because they're polycrystalline," Yakobson said. "For mechanical purposes, like very expensive sandpaper, they're perfect. But for electronics, you would need high quality for it to serve as a wide-band gap semiconductor."

The paper's lead author is Alexander Kvashnin, a former visiting student at Rice and a graduate student at the Moscow Institute of Physics and Technology (MIPT). Co-author Leonid Chernozatonskii is a researcher at the Emanuel Institute of Biochemical Physics at the Russian Academy of Sciences, Moscow. Sorokin holds appointments at MIPT and the National University of Science and Technology, Moscow. Yakobson is Rice's Karl F. Hasselmann Professor of Mechanical Engineering and Materials Science, a professor of chemistry and a member of the Richard E. Smalley Institute for Nanoscale Science and Technology.

The U.S. Air Force Office of Scientific Research, the U.S. Office of Naval Research, the Ministry of Education and Science of the Russian Federation and the Russian Foundation for Basic Research supported the study.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,708 undergraduates and 2,374 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to tinyurl.com/AboutRiceU.

Follow Rice News and Media Relations via Twitter @RiceUNews

For more information, please click here

Contacts:
Mike Williams
713-348-6728

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the abstract at:

Yakobson Group:

Sorokin Group:

Related News Press

News and information

Leti Announces Launch of First European Nanomedicine Characterisation Laboratory: Project Combines Expertise of 9 Partners in 8 Countries to Foster Nanomedicine Innovation and Facilitate Regulatory Approval July 1st, 2015

Bruker Introduces Second-Generation Inspire Nanochemical Imaging Solution: Featuring Unique PeakForce IR and IR EasyAlign Technology July 1st, 2015

GLOBALFOUNDRIES Completes Acquisition of IBM Microelectronics Business: Transaction adds differentiating technologies, world-class technologists, and intellectual property July 1st, 2015

Samsung's New Graphene Technology Will Double Life Of Your Lithium-Ion Battery July 1st, 2015

Govt.-Legislation/Regulation/Funding/Policy

Influential Interfaces Lead to Advances in Organic Spintronics July 1st, 2015

NIST ‘How-To’ Website Documents Procedures for Nano-EHS Research and Testing July 1st, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

Proposed TSCA Nanomaterial Rule ‘Premature’, Says Former EPA Toxicologist July 1st, 2015

Discoveries

Influential Interfaces Lead to Advances in Organic Spintronics July 1st, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

Measurement of Tiny Amounts of Heavy Metals in Baby Food Samples July 1st, 2015

Materials/Metamaterials

Proposed TSCA Nanomaterial Rule ‘Premature’, Says Former EPA Toxicologist July 1st, 2015

NEI Announces the Issuance of Multiple Patents on Self-Healing & Superhydrophobic Coatings June 30th, 2015

BASF and Fraunhofer IPMS-CNT jointly develop electronic materials June 30th, 2015

Green Chemistry Methods Used in Iran to Produce Zinc Oxide Nanoparticles June 27th, 2015

Announcements

Leti Announces Launch of First European Nanomedicine Characterisation Laboratory: Project Combines Expertise of 9 Partners in 8 Countries to Foster Nanomedicine Innovation and Facilitate Regulatory Approval July 1st, 2015

Bruker Introduces Second-Generation Inspire Nanochemical Imaging Solution: Featuring Unique PeakForce IR and IR EasyAlign Technology July 1st, 2015

GLOBALFOUNDRIES Completes Acquisition of IBM Microelectronics Business: Transaction adds differentiating technologies, world-class technologists, and intellectual property July 1st, 2015

Samsung's New Graphene Technology Will Double Life Of Your Lithium-Ion Battery July 1st, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Influential Interfaces Lead to Advances in Organic Spintronics July 1st, 2015

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

Samsung's New Graphene Technology Will Double Life Of Your Lithium-Ion Battery July 1st, 2015

Measurement of Tiny Amounts of Heavy Metals in Baby Food Samples July 1st, 2015

Military

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

The peaks and valleys of silicon: Team of USC Viterbi School of Engineering Researchers introduce new layered semiconducting materials as silicon alternative June 27th, 2015

Opening a new route to photonics Berkeley lab researchers find way to control light in densely packed nanowaveguides June 27th, 2015

World’s 1st Full-Color, Flexible, Skin-Like Display Developed at UCF June 24th, 2015

Research partnerships

Harris & Harris Group Portfolio Company, AgBiome, Announces Partnership to Accelerate the Discovery of Next Generation Insect-Resistant Crops July 1st, 2015

Leti Announces Launch of First European Nanomedicine Characterisation Laboratory: Project Combines Expertise of 9 Partners in 8 Countries to Foster Nanomedicine Innovation and Facilitate Regulatory Approval July 1st, 2015

Carnegie Mellon chemists characterize 3-D macroporous hydrogels: Methods will allow researchers to develop new 'smart' materials June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project