Featured Research

from universities, journals, and other organizations

Diamond in the rough: Half-century puzzle solved

Date:
July 22, 2012
Source:
Yale University
Summary:
A team of mineral physicists has for the first time confirmed through high-pressure experiments the structure of cold-compressed graphite, a form of carbon that is comparable in hardness to its cousin, diamond, but only requires pressure to synthesize. The researchers believe their findings could open the way for a super hard material that can withstand great force and can be used -- as diamond-based materials are now -- for many electronic and industrial applications.

Shadows show severe damage from M-carbon.
Credit: Image courtesy of Yale University

A Yale-led team of mineral physicists has for the first time confirmed through high-pressure experiments the structure of cold-compressed graphite, a form of carbon that is comparable in hardness to its cousin, diamond, but only requires pressure to synthesize. The researchers believe their findings could open the way for a super hard material that can withstand great force and can be used -- as diamond-based materials are now -- for many electronic and industrial applications.

The study appears in Scientific Reports, a Nature journal.

Under normal conditions, pure carbon exhibits vastly different physical properties depending on its structure. For example, graphite is soft, but diamond is one of the hardest materials known. Graphite conducts electricity, but diamond is an insulator.

In the middle is the form of carbon confirmed by the Yale-led team, dubbed M-carbon and predicted by theoretical methods initially in 2006. M-carbon is made when graphite is compressed to pressures approximately 200,000 times room pressure, at room temperature.

Although changes were first observed in graphite under high pressure and room temperature conditions 50 years ago, it is only now that the crystal structure has been confirmed by experiment, using long duration x-ray diffraction, Raman spectroscopy and optical techniques to verify these predictions.

"Besides the unique mechanical properties discovered in M-carbon, we find that the transformation of graphite to M-carbon is extremely sluggish and requires a long time to reach equilibrium, which may be the additional reason why this puzzle remained unsolved for the past half century," said Yuejian Wang, the study's first author and former postdoctoral researcher at Yale, who is now assistant professor of physics at Oakland University.

Researchers say this intermediate structure has much lower symmetry than diamond, but is as hard. In fact, "Our study shows that M-carbon is extremely incompressible and hard, rivaling the extreme properties of diamond so much that it damages diamond," said principal investigator Kanani K.M. Lee, assistant professor of geology and geophysics at Yale.

Lee added, "Over the past few years, many theoretical computations have suggested at least a dozen different crystal structures for this new phase, but our experiments showed that only one crystal structure fits the data: M-carbon."

Other authors are Joseph Panzik of Yale, and Boris Kiefer of New Mexico State University. The study was supported by grants from the Carnegie/Department of Energy (DOE) Alliance Center and by national synchrotron facilities supported by the DOE, National Science Foundation, and the W.M. Keck Foundation.


Story Source:

The above story is based on materials provided by Yale University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Yuejian Wang, Joseph E. Panzik, Boris Kiefer, Kanani K. M. Lee. Crystal structure of graphite under room-temperature compression and decompression. Scientific Reports, 2012; 2 DOI: 10.1038/srep00520

Cite This Page:

Yale University. "Diamond in the rough: Half-century puzzle solved." ScienceDaily. ScienceDaily, 22 July 2012. <www.sciencedaily.com/releases/2012/07/120722145734.htm>.
Yale University. (2012, July 22). Diamond in the rough: Half-century puzzle solved. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2012/07/120722145734.htm
Yale University. "Diamond in the rough: Half-century puzzle solved." ScienceDaily. www.sciencedaily.com/releases/2012/07/120722145734.htm (accessed September 21, 2014).

Share This



More Matter & Energy News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

What This MIT Sensor Could Mean For The Future Of Robotics

What This MIT Sensor Could Mean For The Future Of Robotics

Newsy (Sep. 20, 2014) MIT researchers developed a light-based sensor that gives robots 100 times the sensitivity of a human finger, allowing for "unprecedented dexterity." Video provided by Newsy
Powered by NewsLook.com
MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com
Virtual Reality Headsets Unveiled at Tokyo Game Show

Virtual Reality Headsets Unveiled at Tokyo Game Show

AFP (Sep. 18, 2014) Several companies unveiled virtual reality headsets at the Tokyo Game Show, Asia's largest digital entertainment exhibition. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins