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New form of superhard carbon observed
http://www.physorg.com ^ | 11 Oct 2011 | Provided by Carnegie Institution

Posted on 10/13/2011 10:58:04 AM PDT by Red Badger

Carbon is the fourth-most-abundant element in the universe and takes on a wide variety of forms, called allotropes, including diamond and graphite. Scientists at Carnegie's Geophysical Laboratory are part of a team that has discovered a new form of carbon, which is capable of withstanding extreme pressure stresses that were previously observed only in diamond. This breakthrough discovery will be published in Physical Review Letters.

The team was led by Stanford's Wendy L. Mao and her graduate student Yu Lin and includes Carnegie's Ho-kwang (Dave) Mao, Li Zhang, Paul Chow, Yuming Xiao, Maria Baldini, and Jinfu Shu. The experiment started with a form of carbon called glassy carbon, which was first synthesized in the 1950s, and was found to combine desirable properties of glasses and ceramics with those of graphite. The team created the new carbon allotrope by compressing glassy carbon to above 400,000 times normal atmospheric pressure.

This new carbon form was capable of withstanding 1.3 million times normal atmospheric pressure in one direction while confined under a pressure of 600,000 times atmospheric levels in other directions. No substance other than diamond has been observed to withstand this type of pressure stress, indicating that the new carbon allotrope must indeed be very strong.

However, unlike diamond and other crystalline forms of carbon, the structure of this new material is not organized in repeating atomic units. It is an amorphous material, meaning that its structure lacks the long-range order of crystals. This amorphous, superhard carbon allotrope would have a potential advantage over diamond if its hardness turns out to be isotropic—that is, having hardness that is equally strong in all directions. In contrast, diamond's hardness is highly dependent upon the direction in which the crystal is oriented.

"These findings open up possibilities for potential applications, including super hard anvils for high-pressure research and could lead to new classes of ultradense and strong materials," said Russell Hemley, director of Carnegie's Geophysical Laboratory.


TOPICS: Business/Economy; Culture/Society; Technical
KEYWORDS: allotrope; carbon; diamond; stringtheory
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To: Jonty30
The applications are legion AND it is a use for carbon. In your face Al Gore!

Politicians seem psychologically incapable of understanding how limited their thinking is compared to the producers.

41 posted on 10/13/2011 5:31:16 PM PDT by Aevery_Freeman (The road to hell is paved with plastic.)
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To: KoRn; decimon; neverdem; AdmSmith; bvw; callisto; ckilmer; dandelion; ganeshpuri89; gobucks; ...

Thanks KoRn.
The team created the new carbon allotrope by compressing glassy carbon to above 400,000 times normal atmospheric pressure.
Wow!

Sounds like a nice, lightweight, hard projectile.

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42 posted on 10/13/2011 6:46:28 PM PDT by SunkenCiv (It's never a bad time to FReep this link -- https://secure.freerepublic.com/donate/)
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To: Red Badger
It is an amorphous material, meaning that its structure lacks the long-range order of crystals.

That's speculation, I'm guessing.

One clue is "long range order of crystals", like what is that supposed to mean? Probably not enough of the material has been extensively tested yet.

43 posted on 10/13/2011 6:54:03 PM PDT by bvw
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To: Red Badger

Here’s some bvw dreamland speculations. In such dense fermi-level locked structures, we can quantumly entangle some nuclei and have bound nuclei that become a quantum-resonant mix of nitrogen and carbon. That entanglement might make the structures defiant of X-Ray crystallography, and make it look amorphous, when actually it’s just a denser diamond lattice. You might be able to measure this by decay rates if you have some C-14 in there.


44 posted on 10/13/2011 7:02:12 PM PDT by bvw
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To: Red Badger

They lie.


45 posted on 10/18/2011 7:29:09 PM PDT by allmost
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