New Material Harder Than Diamond 450
h4x0r-3l337 writes "Diamond is no longer the hardest substance known to man. Scientists have created a new material, called "aggregated diamond nanorods" by compressing carbon-60 under high heat. From the article: 'The hardness of a material is measured by its isothermal bulk modulus. Aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), compared with 442 GPa for conventional diamond.'"
Article Text (Score:4, Informative)
26 August 2005
Physicists in Germany have created a material that is harder than diamond. Natalia Dubrovinskaia and colleagues at the University of Bayreuth made the new material by subjecting carbon-60 molecules to immense pressures. The new form of carbon, which is known as aggregated diamond nanorods, is expected to have many industrial applications (App. Phys. Lett. 87 083106).
The hardness of a material is measured by its isothermal bulk modulus. Aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), compared with 442 GPa for conventional diamond. Dubrovinskaia and two of her co-workers - Leonid Dubrovinky and Falko Langenhorst - have patented the process used to make the new material.
Diamond derives its hardness from the fact that each carbon atom is connected to four other atoms by strong covalent bonds. The new material is different in that it is made of tiny interlocking diamond rods. Each rod is a crystal that has a diameter of between 5 and 20 nanometres and a length of about 1 micron.
The group created the ADNRs by compressing the carbon-60 molecules to 20 GPa, which is nearly 200 times atmospheric pressure, while simultaneously heating to 2500 Kelvin. "The synthesis was possible due to a unique 5000-tonne multianvil press at Bayerisches Geoinstitut in Bayreuth that is capable of reaching pressures of 25 GPa and temperatures of 2700 K at the same time," Dubrovinskaia told PhysicsWeb.
The Bayreuth team measured the properties of the samples with a diamond anvil cell at the European Synchrotron Radiation Facility at Grenoble in France. These measurements indicated that ADNRs are about 0.3% denser than diamond, and that the new material has the lowest compressibility of any known material.
In addition to working out why the new material is so hard, the Bayreuth team also hope to exploit its industrial potential. "We have developed a concept for innovative technology to produce the novel material in industrial-scale quantities and now we are looking for partners in order to realize our ideas," said Dubrovinskaia.
Borazon (Score:5, Informative)
Of course, the thermodynamic process to achieve it was far expensive. Required very high pressure and temperatures.
Re:hmmm (Score:5, Informative)
Re:Space Lift? (Score:5, Informative)
You'd probably still use carbon, but nanotubes rather than nanorods.
Re:Borazon (Score:5, Informative)
I wish it was. It would make my job a whole lot easier.
However, it *is* better for grinding ferrous materials than diamond.
--
BMO - Toolmaker
Re:hmmm (Score:5, Informative)
The group created the ADNRs by compressing the carbon-60 molecules to 20 GPa, which is nearly 200 times atmospheric pressure, while simultaneously heating to 2500 Kelvin. "The synthesis was possible due to a unique 5000-tonne multianvil press at Bayerisches Geoinstitut in Bayreuth that is capable of reaching pressures of 25 GPa and temperatures of 2700 K at the same time," Dubrovinskaia told PhysicsWeb.
I was reading that and I thought, 200 atmospheres? What do they need the 5000 ton multianvil press for? They messed it up. 20 GPa is 200000 atmospheres, not 200. [google.com]
Re:Er, what? (Score:5, Informative)
Methods for measuring Hardness (Score:4, Informative)
Re:Er, what? (Score:3, Informative)
For all the people asking how useful this is, take a moment and google for some of comercial applications of diamonds (aside from looking pretty), there are a lot of them. If this stuff can be produced economically there will be a huge market for it.
Re:Does that mean.. (Score:4, Informative)
If we could make a drill out of this new material, doesn't that mean we would have a surplus of diamond to use?
No. Synthetic diamonds were developed by GE in the 50s. Most (if not all) of the diamond in diamond coated drills are produced through this process. The process developed in the 50s only produces what's called "industrial diamonds" and are nowhere near gem quality.
So any new harder substance would only effect the industrial diamond market, and have no effect on the gem quality diamond market.
Re:Diamonds =/= Diamonds? (Score:4, Informative)
Re:hmmm (Score:5, Informative)
Re:Why are you giving us the modulus? (Score:5, Informative)
The hardest scale on the Rockwell test (I'll let someone else give a link somewhere) uses a diamond to make an indent. This works for pretty much everything since diamond is the hardest material.
Until now, at least. Since diamond isn't harder than this, it wouldn't make an indent. No indent, no Rockwell reading.
Re:Stability? (Score:5, Informative)
Eventually, they convert to graphite.
Granted, this will take a (long) while, but it's really more accurate to say graphite is forever.
I don't know about the structure of the ADNR, but it might be even more prone to conversion or sublimation than diamond.
Re:Does that mean.. (Score:5, Informative)
You were OK, sortof. It's not the GE process, but something entirely new (relatively).
Diamond coatings are done through a process called Vapor Deposition. It's a low pressure process, done at Standard Pressure, using a hot carbon rich gas, a reducing atmosphere, and a cold substrate (the thing you're coating).
It's an entirely new process, discovered entirely by accident by someone trying to figure out why certain welds were a bitch to grind smooth. It turned out that there were microscopic diamonds in the welds, and that was why.
--
BMO
Some clarifications on materials and methods (Score:5, Informative)
Most (if not all) of the diamond in diamond coated drills are produced through this process.
There are several processes for putting diamond onto the lap/saw/drill. Some diamonds (natural or synthetic) are brazed onto the material, many saws and diamond wheels actually have diamond impregnated metal so as it wears, cutting action is not degraded and the cheapest method is really close to gluing the damn things to the material. In this instance, it is almost always synthetic. In gem faceting, diamond powder is actually sprinkled onto a lap and rolled into it or used as a slurry.
But as far as "most" goes, "most" diamond tools are not diamond at all but silicon carbide. And even then, it depends on the application for the lap, drill or saw. Depending on the material you are cutting or polishing, natural diamond is preferred to synthetic. This is the case when polishing diamonds and sapphires.
Also, there are a number of "fake" diamonds in the market already, none of which have had any impact on the diamond as a gem. The most common are CZ (cubic zirconia) and Moissanite which is a compressed carbon, also known as silicon carbide, and naturally occurring in meteorites but made for the market in labs. Other "brands" of fake diamonds are usually Moissanite. In diamond testing, cz fails thermal tests, Moissanite passes but fails on conductivity.
Re:Does that mean.. (Score:2, Informative)
Dude, read up on synthetic diamonds. The state of the art has advanced to a point where it is possible to create synthetic diamonds that exceed natural diamonds in purity/and or size, and cheaper as well, and several people are doing it. What color do you like? Blue, yellow, orange, purple, or green?
It's just that supply of 'the real thing' is artificially limited to keep up prices, and the industry has produced equipment to measure exactly what qualities diamonds have. 'Too perfect'? Then it must be an artificial one. Along with the marketing department shouting "synthetic=inferior".
Women like diamonds less just because they're artificial? From what I understand, that's not so clear yet, and many women don't mind. So ofcourse there's low-grade diamond powder produced for things like industrial grinding, but synthetic diamonds can definitely be gem-quality. Strictly speaking, maybe even better.Re:What is it about carbon? (Score:5, Informative)
Carbon is the only element that has these properties (valence 4, high electronegativity) that allow it to form the structures it does. Under extreme pressure and temperature, it's believed that silicon could be coaxed into some kind of polymerization. I remember reading once that a research group managed to polymerize pure nitrogen under megabars of pressure and thousands of degrees F. The result had 3 times the energy density of TNT, and violently decomposed when the pressure was let off - can anyone elaborate or corroborate?
Anyway, hope this helps!
Error in article? (Score:5, Informative)
Re:hmmm (Score:1, Informative)
Re:So, how hard are we talking here? (Score:4, Informative)
So the difference is 11 %. I think whenever you're comparing two quantities, especially when you're not very familiar with the concepts, you can estimate the meaning of the difference by their ratio. Absolute differences are much less meaningful in science.
However, there are some quantities whose number doesn't scale linearly with the physical effect. For example sound pressure (dB scale) and earthquake power (Richter scale) use logarithmic scales, where the absolute difference translates to physical ratio. For example an increase of 10 dB in volume means a 10-fold increase in the physical sound pressure.
Re:Possible uses? (Score:3, Informative)
Re:Ring (Score:3, Informative)
Low-pressure construction? (Score:5, Informative)
The group created the ADNRs by compressing the carbon-60 molecules to 20 GPa, which is nearly 200 times atmospheric pressure
200 atmospheres? That's not much pressure. SCUBA divers regularly put more pressure than that in tanks they wear strapped to their backs.
According to the "units" program on my laptop, 20 GPa is 197,384.65 atmospheres. 200 *thousand* atomospheres... that makes more sense.
Re:Diamonds =/= Diamonds? (Score:5, Informative)
Clearly, they are the same.
I often try to pick up girls by handing them large chunks of coal since it's a diamond, but in a different state. For some reason, they don't seem to go for it. Odd.
Strangely enough, no one will eat my burgers cooked over graphite (and quite frankly, graphite fires are a bit difficult to keep lit).
Carbon is one of the most versitile elements on the planet either alone or combined with other elements. Its quite worthwhile to consider a different state of it a completely different thing.
Re:hmmm (Score:3, Informative)
100000000 Pascals. It's a unit of pressure. It's equal to 1000 bar...
You missed off a zero, and isn't 1 bar equal to 101325 Pascals?
What's the news here? (Score:2, Informative)
Essentially the ultrahard fullerite is a C_60 with unique 3d polymer bonds.
Just check : http://en.wikipedia.org/wiki/Ultrahard_fullerite [wikipedia.org]
Re:Does that mean.. (Score:3, Informative)
Warning, beware of clam.
Compressed Osmium powder. (Score:2, Informative)
Allotropes, not polymers! (Score:4, Informative)
Not the same comparison. (Score:5, Informative)
A gross distortion — about oil. You are basically right about diamonds. While he may overhype matters somewhat, Epstein's classic book [edwardjayepstein.com] documents how the diamond cartel has been ruthless in its limit of supply to a value-sustaining level of marketing-created demand. If supply were to float free, diamonds would drop sharply in price. Furthermore, their intrinsic value within the economy isn't that high-- industrial use mainly. If the US government banned the sale of diamonds for non-industrial uses, DeBeers (and a chunk of the jewelry industry) would collapse, but the overall economy would be OK. Banning the industrial uses would hurt more, and probably trigger a recession, but not a total economic collapse.
Oil, on the other hand, has many uses -- fuel, plastics, fertilizers, and chemical feedstocks probably heading the list. Furthermore, in economic terms, there are NO elasticly substitutable replacements for it, and an exponentially growing demand as China and India become fully industrialized. Since conventional biodiesel relies on petroleum fertilizers and machinery, the "best" elastic replacement is sythetic petroleum from coal, probably becoming competitive in the $120/bbl to $200/bbl range. In the good (?!?) news, this means base (untaxed) gas prices can't do much more than triple from current levels, so we shouldn't go over $10/gallon for gasoline for about 30 years after peak oil (given the vast US coal reserves). The bad news is that the ecologic impacts are higher... which might require higher gas taxes to deal with the impact.
In addition, OPEC (and other cartel) quotas are not the primary limit on supply at this point — although they may be getting rich off it for the moment. Supply today is mainly limited the finite known reserves (with new discoveries having peaked pre-1970), and by current production rate limits (which is why a hurricane in the Gulf caused a price spike of oil to over $70/bbl). OPEC is pretty much pumping as hard as it can now.
Diamond prices are indeed deeply controlled by deliberate supply controls, and there have been times when oil prices were influenced that way, but right now, the price of oil is pure unrestricted supply and demand... where supply is running out.
(Why, yes, I am one of those "Peak Oil" kooks. Pleased ta meetcha.)
Re:hmmm (Score:3, Informative)
Not according to either Wikipedia [wikipedia.org] or google [google.com.au].
You're making the mistake of thinking that standard atmospheric pressure is 1 bar, it's actually 1.01325 bar (or 1013.25 millibar)
(and yes, I missed a zero)