Computer simulations suggest graphynes may be even more useful than graphene

Mar 05, 2012 by Bob Yirka report
The carbon lattice in this 6,6,12-graphyne has a rectangular symmetry, unlike the hexagonal symmetry of graphene. Image: D. Malko et al., Phys. Rev. Lett. (2012)

(PhysOrg.com) -- The past several years have seen a virtual explosion in the amount of research dedicated to graphene and as a result there has been a nearly constant stream of news pertaining to new discoveries regarding its attributes. Now it appears, graphene is about to be upstaged by a more interesting cousin called graphyne. Graphene, as most everyone is aware by now, is a single layer of carbon atoms arranged in a hexagonal or chicken-wire pattern. Graphyne is also a single layer of carbon atoms, but it comes in several different types of patterns, which likely make it more versatile. Now new computer simulations regarding its properties have been done by a team of researchers in Germany, who report in Physical Review Letters, that their research shows that some types of graphyne structures allow for electron flow in just one direction.

Greaphene, it has been noted, has conduction electrons whose energies are directly proportional to their momentum. It has also been noted that when their energy levels are plotted in three dimensions, they take on the shape of a Dirac cone. Because of this unique relationship, the conduction electrons behave as if they were massless, allowing them to travel at very near the speed of light, a very useful property when looking to improve on such things as current .

Unlike graphene, which has single or , graphyne can have double or triple bonds, and it’s not restricted to just a hexagonal pattern. Indeed the number of patterns that it can exist as appears to be almost limitless.

In this new research, the team looked at three graphyne pattern types with their computer simulation and found all of them capable of producing a Dirac cone, albeit in a slightly different shape; but perhaps most importantly, one of them called 6,6,12-graphyne, which exists as a pattern of rectangles, should allow electrons to travel in just one direction. Because of this, the researchers say, materials could be made that didn’t require “dopant” or nancarbon atoms to provide a source for the electrons, such as the case with graphene.

Despite the fact that only very small pieces of graphyne have ever been made, researchers are excited about this research because it has shown that many graphyne pattern types exist that are capable of producing a Dirac cone, which means many other materials may be capable of doing so as well.

Explore further: Nanomaterial outsmarts ions

More information: Competition for Graphene: Graphynes with Direction-Dependent Dirac Cones, Phys. Rev. Lett. 108, 086804 (2012) DOI: 10.1103/PhysRevLett.108.086804

Abstract
The existence of Dirac cones in the band structure of two-dimensional materials accompanied by unprecedented electronic properties is considered to be a unique feature of graphene related to its hexagonal symmetry. Here, we present other two-dimensional carbon materials, graphynes, that also possess Dirac cones according to first-principles electronic structure calculations. One of these materials, 6,6,12-graphyne, does not have hexagonal symmetry and features two self-doped nonequivalent distorted Dirac cones suggesting electronic properties even more amazing than that of graphene.

via Focus

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User comments : 26

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antialias_physorg
4 / 5 (4) Mar 05, 2012
materials could be made that didnt require 'dopant' or nancarbon atoms to provide a source for the electrons

Now this would be truly revolutionary. It would make a single step process for manufacturing electronics possible. Cheap, bendable - probably transparent - next to no resistance... hell, this stuff has got it all.
Kinedryl
1 / 5 (1) Mar 05, 2012
Even if this compound could exist, it may not provide a better electric properties than the graphene. The regularity of structure is the key for high carriers mobility. The more different structures the charge carriers have in their path, the more they will be dispersed during their travel, so that their mobility and free path will decrease. http://physicswor...ws/48385
hjbasutu
3 / 5 (2) Mar 05, 2012
Do physcists ever rest....i doubt
antialias_physorg
5 / 5 (5) Mar 05, 2012
Do physcists ever rest....i doubt

Sometimes they really don't. A lot of the scientific work is done by PhD students.

And if my own past experiences (and those of the about 30 fellow PhD students at the same institute) are anything to go by then there are days/weekends (and towards the deadline fo your PhD thesis entire months) where you don't see the sun at all.

It's not a healthy lifestyle at times. But then again what is when you do something for which you feel highly motivated (to avoid the phrase 'driven'... )
TabulaMentis
1 / 5 (2) Mar 05, 2012
Now this would be truly revolutionary. It would make a single step process for manufacturing electronics possible. Cheap, bendable - probably transparent - next to no resistance... hell, this stuff has got it all.
I just cannot wait until we can do this on the ultramicroscopic (preatomic) level. Now that is when all hell is going to break loose.
axemaster
not rated yet Mar 05, 2012
So are these alternate structures stable? I should think that would be the most important question...
antialias_physorg
not rated yet Mar 05, 2012
(preatomic) level.

What does that even mean?

So are these alternate structures stable?

Since they have already been created in the lab (as the article states) it seems they are stable.
TabulaMentis
1 / 5 (2) Mar 05, 2012
What does that even mean?
Of or belonging to the time before the use of, existence of, or capability for atomic energy or weapons.

http://www.thefre...reatomic
Kinedryl
3.7 / 5 (3) Mar 05, 2012
Do physcists ever rest....i doubt
There is whole army of them. Actually, the news at the PhysOrg are just a tip of iceberg. For every scientific article presented at mainstream news you can find dozens of more specialized ones at ArXiv and another sources. I'm pretty sure, many scientists cannot handle the information flow even in their narrow range of specialization. You'll need a simple, yet effective meta-theory or paradigm to orient yourself inside of fast expanding ocean of information (a foamy density fluctuations enabling the propagation of information at distance so to say).

We shouldn't forget, despite this frenetic activity of physicists the practical applicability of these results is very low. We even don't have a single molecule of graphyne. It's merely an informational noise from perspective of practical applications.
Lurker2358
1 / 5 (2) Mar 05, 2012
(preatomic) level.

What does that even mean?


I think he means "subatomic", as in building stuff out of protons, neutrons and other fundamental particles directly, instead of using atoms and molecules.

For example, Hypernuclei, etc, might allow some freaky physics or exotic structures or meta-molecules if you could mass produce them and do chemistry with them.

I'd say we've got quite a while to go before anything like that is possible, never mind mainstream practice.

It is interesting to find a new lattice for Carbon which may have interesting structural, thermal, and electrical properties.

Someone is bound to find useful applications for these materials, eventually.
antialias_physorg
not rated yet Mar 05, 2012
as in building stuff out of protons, neutrons and other fundamental particles directly, instead of using atoms and molecules.

And this is going to work...how?
Electric forces are strong. Protons and electrons want to pair up to form atoms. To give you an idea how strong the electric force is that attracts these two:
It's a million million million million million million times stronger than gravity (no typo. That's 36 orders of magnitude).

Or as Feynman once calculated it in a lecture: If you and I stand 10 meters apart, and we each have just 1% excess electrons (or protons) we would repel by a force adequate to lift an entire Earth off the Earth(!)
TabulaMentis
1 / 5 (2) Mar 05, 2012
I think he means "subatomic", as in building stuff out of protons, neutrons and other fundamental particles directly, instead of using atoms and molecules.
No. Quarks, protons, neutrons and electrons are made of preatomic particles. Dark matter is also made of preatoms, however they are not composite particles, sort of. They are both fermonic and bosonic.

See the previous description again:

Of or belonging to the time before the use of, existence of, or capability for atomic energy or weapons.

http://www.thefre...reatomic
antialias_physorg
3 / 5 (2) Mar 05, 2012
Of or belonging to the time before the use of, existence of, or capability for atomic energy or weapons.

Erm...that use of the term "preatomic" refers to human history. It denotes the time of civilization from stone age axes (and before) to coal power plants in times of the industrial revolution.
Lurker2358
1 / 5 (2) Mar 05, 2012
as in building stuff out of protons, neutrons and other fundamental particles directly, instead of using atoms and molecules.

And this is going to work...how?
Electric forces are strong. Protons and electrons want to pair up to form atoms. To give you an idea how strong the electric force is that attracts these two:
It's a million million million million million million times stronger than gravity (no typo. That's 36 orders of magnitude).

Or as Feynman once calculated it in a lecture: If you and I stand 10 meters apart, and we each have just 1% excess electrons (or protons) we would repel by a force adequate to lift an entire Earth off the Earth(!)


I know this.

I'm talking about exotic nucleus configurations which have been discovered in particle accelerators, which may lend themselves to lighter or stronger building materials, perhaps by being "stable" with a lower number of neutrons, or some other spooky phenomenon.

Imagine a stable isotope of Element 118.
TabulaMentis
1 / 5 (4) Mar 06, 2012
Erm...that use of the term "preatomic" refers to human history. It denotes the time of civilization from stone age axes (and before) to coal power plants in times of the industrial revolution.
You are viewing it from the macroscopic scale. I am viewing it from the ultramicroscopic scale.
antialias_physorg
5 / 5 (1) Mar 06, 2012
which may lend themselves to lighter or stronger building materials, perhaps by being "stable" with a lower number of neutrons, or some other spooky phenomenon.

It takes oodles of power to create these. Individually. You have any idea how many atoms are in even a gram of matter? That's pretty unrealistic to create atoms from scratch to have some exotic properties for mainstream applications.

Not in this lifetime.

I am viewing it from the ultramicroscopic scale.

Nope. You just confused subatomic with preatomic (and no. You can't build stuff out of subatomic particles)
TabulaMentis
1 / 5 (2) Mar 08, 2012
Nope. You just confused subatomic with preatomic (and no. You can't build stuff out of subatomic particles).
No, I have not confused anything. Preatomic means before atomic energy, including subatomic. I have been using the term "preatomic" for twenty-one years, maybe even longer than the Internet dictionaries. You sound old-fashioned and not willing to allow for new ideas, including new words, or new definitions to existing words.
antialias_physorg
1 / 5 (1) Mar 08, 2012
Preatomic means: before the INVENTION or USE OF of atomic energy.

[qI have been using the term "preatomic" for twenty-one years
Well, then you've been using it wrong for twenty-one years. Because all english speakers and all dictionaries disagree with your definition.

You may call an apple a banana for twenty years. But that doesn't make it correct that an apple should be called a banana.

This has nothing to do with being 'old fashioned'. It just has something to do with knowing what words mean.
TabulaMentis
1 / 5 (2) Mar 08, 2012
It just has something to do with knowing what words mean.
I have created over 500 words to explain things that there are currently no words. If you do not like the word "preatomic" in the contexts in which it is being used, then that is too bad.

If you have a better word to explain what I am talking about, then spit it out!
antialias_physorg
1 / 5 (1) Mar 09, 2012
I have created over 500 words to explain things that there are currently no words.

And not a single one has caught on. that should tell you something.

Making up words is all fine and dandy as long as you're in your own head (and whatever for would you need to make up words when you're only talking to yourself? YOU know what you mean.).

But when talking to real people in a real world? You might want to use real language.

If you have a better word to explain what I am talking about

There are a lot of real words that denote subatomic particles: E.g. fermions, quarks, bosons, hardons, leptons, baryons, mesons, ...

If you don't mean any that fall under those kinds of categories then you probably need to visit a physics class or write a paper on your revolutionary findings.
TabulaMentis
1 / 5 (1) Mar 11, 2012
@antialias_physorg

I was talking about the subject of "Zero-dimensional Space" about a year ago or so with Physorg.com members. Everyone argued with me about how stupid the idea of Zero-dimensional Space was. Now you can find a Web page on the subject at Wikipedia although Im not sure its definition is what I was talking about. See the following link:

http://en.wikiped...al_space

I'm sure the word Preatomic will pop-up on Wikipedia before you know it.

You keep on equating preatomic particles with atomic and subatomic particles. Again, preatomic particles are what atoms; including subatomic particles, are made from. If that surprises you, then the string theorists do it all the time by saying atoms, including subatomic particles, are made of tiny closed strings that vibrate.

I will take your advice on writing a paper, whatever that may be. I have already created and copyrighted the Theory of Everything (ToE) and the equation for the ToE.
Callippo
1 / 5 (1) Mar 11, 2012
Zero dimensional space is a common concept of dense aether model, in which energy dispersion gradually loses a dimensionality in similar way, like the ripples at the water surface or waves spreading through particle foam. The waves use a surfaces (membranes) of foam, then the one dimensional string network and at the very end they're spreading with collisions of individual particles. The longitudinal waves are zero-dimensional waves for transverse waves and nothing mysterious is about it.
antialias_physorg
1 / 5 (1) Mar 11, 2012
was talking about the subject of "Zero-dimensional Space" about a year ago or so with Physorg.com members.

So, let me get this straight: you said something (totally unrelated to what we are discussing) a year ago. That phrase pops up somewhere on the web - but in a sense that is again different from what you meant at the time.
And this is supposed to be an argument FOR you using words different than all 7 billion people on this planet?
If you think THAT is logic FOR your argument then you are completely screwed up.

(and BTW: a zero dimensional space is a topological construct. It's an abstract, mathematical IDEA. Not a model of reality)

I have already created and copyrighted the Theory of Everything

So why are you on a forum? You should be in Stockholm. Oh wait...you aren't ..because you're a crank.
Callippo
1 / 5 (1) Mar 11, 2012
a zero dimensional space is a topological construct.
It's abstract construct for abstract people, but it has physical roots. After all, like the space itself: you cannot have a geometry without physical space, which makes the geometry a bit more relevant to physics, than just pure math.
If we compress the dense supercritical gas, then a foamy density fluctuations will emerge. The energy will spread along surface (mem)branes of this foam, i.e. in two dimensional form. When we heat this gas, these density fluctuations will dissolve. Their dissolving will proceed gradually, though. At first, the membranes dissolve, only their linear connections will remain, so that the energy will be transferred along string net. And if you heat this mixture even more, only 1D particles will remain. In this way the phase transitions and changes in dimensionality of space-time can be modeled with particle environment.
Callippo
1 / 5 (1) Mar 11, 2012
errata: "only 1D particles will remain" should be "only 0D particles will remain" indeed. The zero dimensional space is effectively the aether space composed of particles, where the energy propagates via mutual collisions of particles, rather than along density gradients between them.
TabulaMentis
1 / 5 (2) Mar 11, 2012
If you think THAT is logic FOR your argument then you are completely screwed up. So why are you on a forum? You should be in Stockholm. Oh wait...you aren't ..because you're a crank.
reportquote.
I used zero-dimensional space as an example of the past in which people like you who did not know what I was talking about. I will lay it out to you one more time. There is zero-dimensional space, one-dimensional space and two-dimensional space. There are also "Preatoms." Take it or leave, it's your choice!

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