Slashdot Mirror
Carbon Nanotubes Harder Than Diamond
purduephotog writes "CDAC has announced the formation of a new form of hexagonal packed carbon similiar to diamond. Carbon nanotubes are compressed at 75 GPa and quenched. The new material is conclusively different via Raman Spectroscopy and both cracked and indented the diamond anvil used in its creation. CDAC is also known to have created via CVD the hardest diamond to date."
Does it go to 11?
The key difference between a Programmer and a Senior Programmer is that one of them is Mexican.
I've never done a spectroscopic analysis of ramen before - I usually just ate it
to spell out Chemical Vapor Deposition?
Overuse of acronyms degrade language, you know.
I cant see them becoming a girls best friend though
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
Raman Spectroscopy
Dude, they're always tough until you boil them for 3 minutes. This is nothing new.
Pulp Audio Weekly - Geek News and Reviews
This might be good for new machining tools?
I wonder what the optical properties are, and what the maximum size of these is?
OK great. Everytime diamonds/gems are mentioned in any way here on /. I get the familiar sound coming up from my computer room of "Honey, take a look at this. I bet NOBODY else at work would have one of these." Followed by a batting of the eyelashes and a subsequent emptying of my bank account. Please oh please stop mentioning these!!!
Oh well, there is usually at least a sexual favor in there somewhere as well. Here's to hoping!!!
Knightfall
Am I the only one who chuckled upon seeing the file name "wang_pnas.pdf"? TGIF
And thus, the student overtakes the master.
Ut Tensio, Sic Vis
Here on the planet Klepton, we've built our saucer hulls out of this stuff for decades. You Earth scientists are so retarded. Except for the one who invented Twinkies. He's cool.
These are the types of advances we need to make the space elevator a reality. Either using nanotubes like this in a matrix, or more mind-boggingly, create wires of them.
Going up!
...or maybe not.
Raman, the technology and dietary staple of millions of college students makes carbon nanotubes harder than diamonds, (but still not harder than the $.25 cent Raman noodles themselves)
Now we have drills to carve parts from synthetic diamonds. Very tiny drills, for very tiny machined parts. This nanotech is starting to get good.
--
make install -not war
I realize you are kidding... here is what Raman really is... (give or take a few details ;p)
Spectroscopy: study of quantities of light at various wavelengths (or frequencies). Useful because matter interacts with light, so by measuring light passing through unknown matter, you figure out what its passing through.
Raman spectroscopy, is a branch where one looks at the wavelength shift occurring as light passes through a sample. A bit like doppler radar involves a shift of frequency (although it's not a shift due to the movement of molecues, but rather due to energy differences in orbitals as they move/distort).
The cool thing about Raman is that you just need a single wavelength of excitation, meaning you can build a spectrometer with a single laser diode. Then you filter off the laser line, and presto, the only light left will be the spectrum of interest.
Caveats: low intensity, frequency shift is very small, you still need a monochromator. Advantages: you get information that isn't available in standard IR & UV-vis spectra, the spectra are excitation freuency independant (not entirely true), by taking advantage of resonances it's possible to get REALLY intense spectra (resonance Raman and SERS).
I am still waiting for synthetic diamonds to break De Beers' cartel.
Damn... Just when I get my +5 sword diamond bladed, they make a better diamond... or rather, carbon thingy
Only the purest of souls seek enlightenment. Everyone else just wants power.
The 2001 edition of the annual review of materials research, http://www.annualreviews.org/, has a nice review of the field of super hard materials. the authors point out that scratching a diamond is not, in intself, much evidence of anything; in the real world lots of soft scratch hard examples can be found. The authors of this article also point out that one of the few flaws of diamond is that it reacts with iron, so you can't diamond coat cutting tools; instead, you have to use much softer things like boron nitride or TiN. Nanotubes could have a major commercial future if they are harder then TiN, non reactive to iron, but softer then diamond.
full citation SYNTHESIS AND DESIGN OF SUPERHARD MATERIALS; J Haines, JM Léger, G Bocquillon
Annual Review of Materials Research, Vol. 31: 1-23
How can this possibly be modded as informative? Refering to Superman as evidence and then posting a link that only talks about diamond finds around the great lakes does not convince me of the posters veracity.
"Prefiero morir de pie que vivir siempre arrodillado!"
Geez, now us guys have to buy our fiancees Carbon Nanotube Engagement rings?
Yeesh. No. There are just a few other problems, as with all ideas hatched by Scifi authors (who need to do little more than make something plausible on the most abstract level. Scifi authors almost always get it WRONG- we don't all use jetpacks and atomic cars to get to work, now do we? No 'death rays'- hell, we haven't even gotten speech recognition down, really).
I know some -other- fanboy will link to a FAQ that "answers"(says, for each issue, "we're aware of it and working on it!") each of these, but:
...all of these issues stacked against the relative ease of launching things into space (used to be a big deal. Now it's pretty ho-hum). Nevermind the main benefit everyone always cites (conveniently leaving out all costs except the actual energy needed to lift something- wow, a business like that with no overhead? Cool). Cutting the $/lb price by ten, is not going to mean 10x more stuff in space to put up. God, I hope not, it's cluttered as is...
Let the "flamebait" and "troll" mods who are Space Fanboys begin, for thou shalt not speak out against space development even if it IS a legitimate viewpoint- and one shared by many of us. Let's be a little more, uh, down to earth in our problem solving, please? We've got a lot of problems right here on earth, folks- and I'd much rather you all put that brainpower to them.
Please help metamoderate.
Wait, what does AC stand for again?
I think the abstract said "at least comparable to cubic diamond".
That would change Mohs hardness scale if it were harder.
"Rocky Rococo, at your cervix!"
And best of all, no African peasants had to die to make these.
This message brought to you by the Council of People Who Are Sick of Seeing More People.
...and enough with the nanotube ring jokes. That's not what I'm talking about.
You see, nowadays, when you want to facet a gemstone into the shapes most people have come to expect in jewelry, one has to use abrasives to put the faces in the stone. Usually Silicon Carbide grit (9.5 hardness, usually for softer stones) or diamond (10 hardness, for harder stuff) on a spinning disk to grind into the stone. But this doesn't work for all gemstones, notably diamond. Trying to facet a diamond with diamond grit on a lap (the disk) will just cut gouges into your lap. They are not cheap.
So diamonds still have to be done the hard way: roughly shaping the stone by cleaving, then using 2 diamonds, one of poor quality, to rub the faces into the good diamond. If this stuff can be synthesized in different grits (particle sizes) for fairly cheap, then it can be used to facet diamonds with machinery rather than by hand. Much of a diamonds (and most other stones) value is actually from the labor put into faceting it. This is especially so for smaller stones. How cheap? Well, currently lapidaries are paying for synthetic diamond grit...
Any sufficiently advanced influence is indistinguishable from control.
For humans, J. Storrs-Hall (of sci.nanotech fame) proposed a space railway that could be built sooner and more cheaply than a space elevator. It's a linear induction motor laid along a 300km-long track, 100km above the ground, where the atmosphere is thin enough to take a few orbits to decay your orbit. You drive your spaceship up a ramp to one end, and the motor accelerates you along the railway at about 10G for about 90 seconds, putting you in a slightly elliptical orbit with an apogee on the other side of the Earth. When you hit apogee, you do a burn to get into a higher orbit.
Relatively little radiation because you cross the Van Allen belts much faster. You get to LEO without burning any of your own fuel, which is a big energy win. The railway is low enough that orbits still decay slowly, so there's no space junk to worry about at that altitude.
The structure is a collection of A-frames, built like a radio tower. Like the space elevator, only a tiny fraction of the height is subjected to significant weather. The structure is under compression, not tension, which widens the choice of materials. According to Storrs-Hall, existing synthetic diamond would be suitable.
WWJD for a Klondike Bar?
Keep in mind the compressive strength of a material is not the same as the strenth in tension. Not only that material like this has pretty much no elastic properties. ie, thats why you can easily shatter a diamond even though it's so strong
Have you ever seen a ring made of 24K gold that's been worn for a while? Pure gold isn't much harder than lead and will get beaten up in a hurry. 14-18K is much better suited to everyday jewelry. Although it is a pretty crappy alloy that would turn fingers green.
"Prefiero morir de pie que vivir siempre arrodillado!"
I'm expecting 2 more dupes of this article.
I can pronounce "CVD" as a word, so it must be an acronym. That I almost coughed my liver up as a result of said pronunciation has no bearing on that fact, from my point of view...
Constitutional rights may be respected, repealed, or modified; but they must never be ignored.
> It looks like diamonds aren't forever.
And they never were. Diamonds burn and don't even leave ash, they turn to CO2. This was known to the Romans. DeBeers was irresponsible by claiming that diamonds last forever. Diamond combusts at 1320 degrees. Jewelers coat diamonds to seal out oxygen when soldering.
Diamond is overrated. Graphite is more stable. Cubic Zirconia requires much higher temperatures to combust. For industrial applications, synthetic diamonds are generally superior. If you're buying sex, it can be had more cheaply. There's really no good reason to ever purchase a jewelry diamond, and lots of reasons not to.
-fb Everything not expressly forbidden is now mandatory.
..that I was listening to a radio show the other day, and this was the topic. Turns out that *most* (not all but most) of the high level opposition to "blood diamonds" comes from the debeers monopoly itself, they started it as a disinformation campaign, and have used a lot of mercenaries to instigate violence against a lot of poor people just trying to dig up a buck or two. turned them into rebels and terrorists and such like. Various folks ran with this disinformation and now it's carved in stone "fact". Reality is diamonds are more common than some other precious stones, they just keep a higher market value from the dearth of competition and a lot of industry collusion.
anyway, that's what was on the show....
hey! searching google to look for some data to backup what I just remembered anecdotally found me this gem!.