Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New material breakthrough: Super-hard graphite cracks diamond

17.10.2003


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. Use of the HPCAT facility at Argonne National Laboratory for this work was funded by the Department of Energy, the National Nuclear Security Administration, the National Science Foundation, the Department of Defense, the W.M. Keck Foundation, and the Carnegie Institution of Washington.

The Carnegie Institution of Washington (www.CarnegieInstitution.org) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments in the U.S.: Plant Biology, Global Ecology, The Observatories, Embryology, the Department of Terrestrial Magnetism, and the Geophysical Laboratory.

Wendy Mao | EurekAlert!
Further information:
http://www.CarnegieInstitution.org

More articles from Materials Sciences:

nachricht Scientists channel graphene to understand filtration and ion transport into cells
11.12.2017 | National Institute of Standards and Technology (NIST)

nachricht Successful Mechanical Testing of Nanowires
07.12.2017 | Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>