Super-Hard Graphite Cracks Diamond

NANO TECH

carbon is the only element that comes in three distinct forms - graphite, diamond and carbon-60 buckyballs

Washington - Oct 17, 2003
It is hard to imagine that graphite, the soft "lead" of pencils, can be transformed into a form that competes in strength with its molecular cousin diamond.

Using a diamond anvil to produce extreme pressures and the ultra-brilliant X-ray beams at the Advanced Photon Source in Illinois, scientists with the High-Pressure Collaborative Access Team (HPCAT)* have surmounted experimental obstacles to probe the changes that graphite undergoes to produce this unique, super-hard substance. The study is reported in the October 17, issue of Science.

"Researchers have speculated for years on the extreme conditions that might change the molecular structure of graphite into a super-hard form that rivals diamond," said Wendy Mao, the study's lead author from the Carnegie Institution's Geophysical Laboratory in Washington, D.C., and the University of Chicago.

"This experiment is the first to determine quantitatively how the bonding in graphite changes under high-pressure conditions. Conventional methods limited our observations to surface studies of the material," she stated.

"Now, with the super high-intensity X-rays of the Argonne facility and with our team's technology to focus the entire beam to a small spot, we've been able to look at the material in the diamond-anvil cell while under high pressure. We've overcome the obstacles of the past," she concluded.

Graphite and diamond are both made of carbon. The geometric arrangement and spacing of the carbon atoms is what makes the materials differ in appearance and strength. The atoms in graphite are arranged in layers that are widely spaced. The atoms in diamond, on the other hand, are tightly linked producing a strongly bonded structure.

The HPCAT scientists subjected graphite to pressures that are equivalent to 170,000 times the pressure at sea level ( 17 gigapascals). "We were able to see how the structure changed at the atomic level when the graphite was squeezed into the super-hard form," remarked co-author Dave Mao of Carnegie's Geophysical Laboratory.

"The graphite that resulted from our experiment was so hard that when we released the pressure we saw that it had actually cracked the diamond anvil."

The super-hard from of graphite opens the door to a myriad of applications in industry particularly as a structural component.

HPCAT is made up of researchers from the Carnegie Institution's Geophysical Laboratory, the High-Pressure Physics Group of the Lawrence Livermore National Laboratory, the High Pressure Science and Engineering Center of the University of Nevada, Las Vegas, and the University of Hawaii Institute of Geophysics and Planetology.

NANO TECH

Buckyball Carbon Brings Light Into Line

Toronto - Sep 15, 2003
Using molecules resembling 60-sided soccer balls, a joint team of researchers from the University of Toronto and Carleton University has created a new material for processing information using light.

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.