Lithium graphene is truely superconductive

[PB666]

http://phys.org/news/2015-09-graphene-superconductive-doping-lithium-atoms.html

[NFUN]

It only has demonstrated one property of superconductivity as of now. More tests will be done later, but there isn't enough information to call it 'truely [sic] superconductive' yet.

[AngelLestat]

Ah, but this happen at 6kelvin :S

Graphene already has very good conductive properties, but if we want superconductivity, there are many other possibilities in materials.

[Mazon Del]

Did they actually say 6 Kelvin? Or was it something else?

[Shpaget]

those samples were then placed in a vacuum and cooled to 8K and were then "decorated" very precisely with a layer of lithium atoms

This result suggests for the first time, to our knowledge, that Li-decorated monolayer graphene is indeed superconducting with Tc≃5.9K.

They do say it in abstract.

[PB666]

They do say it in abstract.

The thing about graphene is that its relatively easy to make and doesn't require any rare metals. Since its starts out as very conductive and very young I would assume that you will see the maximum operational temperature rise. The other thing is that you can stack them in layers of about 3A, not withsanding the radius of the lithium so that you can literally stack superconducting being critical lets say 20A per layer that is roughly 500,000 widings per millimeter, think about what kind of transformer or supermagnet you could make in a fairly small space.

[Ralathon]

Since its starts out as very conductive and very young I would assume that you will see the maximum operational temperature rise.

That's not really how superconductivity via cooper pairs works. The creation of cooper pairs that allow for superconductivity depend on the material used. If you want a higher temperature you can't just toss more science at it, you need to find a different material. 6K is pretty bad for a superconductor, simple lead becomes a superconductor at 7.2K.

Also, you can't pump 3 amps through a monoatomic layer. Superconductivity is a fragile beast and it will collapse if you try to push too much current. High currents means high magnetic fields and high magnetic fields kill superconductivity. A very low temperature means you don't have much leeway in your critical field. So this graphene lithium superconductor will probably suck at conducting high amps.

[PB666]

That's not really how superconductivity via cooper pairs works. The creation of cooper pairs that allow for superconductivity depend on the material used. If you want a higher temperature you can't just toss more science at it, you need to find a different material. 6K is pretty bad for a superconductor, simple lead becomes a superconductor at 7.2K.

Also, you can't pump 3 amps through a monoatomic layer. Superconductivity is a fragile beast and it will collapse if you try to push too much current. High currents means high magnetic fields and high magnetic fields kill superconductivity. A very low temperature means you don't have much leeway in your critical field. So this graphene lithium superconductor will probably suck at conducting high amps.

I wan't thinking about lithium graphene so much, i was thinking in terns of layering other metal molecules on top. Simple lead cannot form such a thin monolayer, and as a conductor lead is a very poor choice in space, particularly compared with lithium and carbon. But to the point, the 4n + 2 orbital can be accessed at several points along the graphene sheet edge so it can be thin and wide and in that context a monolayer could conduct an infinite number of amps. if you could take a 20 guage wire and widen it 40 times and flatten it 100000 times you could spread out the ends to make an excellent high amperage contact, your transformer can have 2500 times the number of windings which means you could turn a 10x stepup thnsformer and turn it into a 25000x step up transformer. Or alternatively create a significantly stronger electro magnet.

The 7 degree is not high, but graphene has benn on the edge of superconductivity, its good to see someone has cross the line and I expect more progress to be made.

[GDJ]

.....So this graphene lithium superconductor will probably suck at conducting high amps.

Damn! So much for new speaker wires anytime soon. I guess I'll stick to 12 ga. Copper.

[Stargate525]

Damn! So much for new speaker wires anytime soon. I guess I'll stick to 12 ga. Copper.

And good luck cooling your speaker wires to 6 Kelvin...

[K^2]

Also, you can't pump 3 amps through a monoatomic layer. Superconductivity is a fragile beast and it will collapse if you try to push too much current. High currents means high magnetic fields and high magnetic fields kill superconductivity. A very low temperature means you don't have much leeway in your critical field. So this graphene lithium superconductor will probably suck at conducting high amps.

It's not usually the mag field that kills superconductivity directly at high Amps. Though, obviously, that's one of the limiting factors. What you really end up with is a critical surface in the T-H-I space. So the closer you get to T_C, for example, the less mag field and current the material can withstand before transitioning. Which is why vacuum pumps are a common feature of modern SC magnet. They help drop temperature to the 1K-2K ranges, allowing for higher critical fields and currents.

Long story short, yeah, you won't be pushing amps through a grephene sc. In fact, I'm not quite clear on what the point is. We have great HTSCs, and way, way better conventional SCs as well. When I saw an article, I was expecting to see some absurdly high T_C, maybe even room temp, but then I saw the 5.9K, and the only question I have is why anyone bothered reporting this?

[PB666]

It's not usually the mag field that kills superconductivity directly at high Amps. Though, obviously, that's one of the limiting factors. What you really end up with is a critical surface in the T-H-I space. So the closer you get to T_C, for example, the less mag field and current the material can withstand before transitioning. Which is why vacuum pumps are a common feature of modern SC magnet. They help drop temperature to the 1K-2K ranges, allowing for higher critical fields and currents.

Long story short, yeah, you won't be pushing amps through a grephene sc. In fact, I'm not quite clear on what the point is. We have great HTSCs, and way, way better conventional SCs as well. When I saw an article, I was expecting to see some absurdly high T_C, maybe even room temp, but then I saw the 5.9K, and the only question I have is why anyone bothered reporting this?

because you can do this

http://www.wired.co.uk/news/archive/2015-08/10/graphene-3d-printed-super-batteries

[Mazon Del]

But this article didn't exactly aid the idea that graphene can be used to make super batteries. We already knew that, and a battery that requires you to spend an absurd amount of energy just to keep it in a special state is not necessarily very useful.

[PB666]

But this article didn't exactly aid the idea that graphene can be used to make super batteries. We already knew that, and a battery that requires you to spend an absurd amount of energy just to keep it in a special state is not necessarily very useful.

No, you don't get it, Graphene is flat, really flat, in fact its one of the flattest things we know of, the pi* 4n+2 orbitals stick out 1A on either side, the lithium adds another 1.5A on either side. But without lithium, in nature 4n + 2 orbitals love to stack, that stacking explains the double helical nature of DNA. They like to point the hole of those little donut orbitals at each other (grand oversimplification). You can roll graphene ever so slightly creating a wrap, and if you can do that you can create and electromagnet with many many windings. And graphene can potentially be made very long. In space if you were to print out graphene and let it roll out into an hv free area, the 4n+2 orbitals would be perfectly flat following space-time curvature, forever. And if you place an electron on one end and test the voltage potential at the other end, that EMF immediately appears, because according to one report, the lowest potential energy 4n +2 orbital is a quantum singularity.

Imagine a 3D printer that can print graphene, and it is printing a graphene sheet on a very smooth thread spool used for a sewing machine, and while it is printing I am turning it so that when I am done I put 500,000 windings on it. Lets say with molecular (metal alloy) appending that thickness reduces to 50,000 but I can gain superconductivity, that means I have say 50,000 windings. At the ends I spread the superconducting graphene out into a wide area of regular graphene that then I connect to my powersupply (basically the relay would be like a flat pole you might find in any household distribution center), somewhat tricky because you would have to fork the interior most winding out and turn it backwards. With proper terminal insulation I could place 0.1V on that assume the maximum amperage I can place at the poles is say 125 Amps (limit of most residental distribution centers), calculate the EMF on say a magnetizable supermetal place in the center hole of the spool. Then you get it.

So now if each graphene hexagon is spread 4A apart and I have a 4 centimeter of graphene that means on each hexagon I am dropping 125A across 10⁶ (.125 millamps per hexagon) contact points of superconductive material or if I connect this with non-superconductive graphene at room temperature, the contact might be a 0.4 meter (.0125 millamps per hexagon). So basically the transformer that powers your house is doing roughly the same thing, but its about a meter high and a third of a meter wide, and embedded in really dangerous oil (most of the environmental PCPs came from transformers of that like), and I am basically doing half of that with a sewing machine spool sized device. We have to assume via Quantum mechanics that we can dump 1 electron onto the orbital at the rate of 1/10^-43 sec , and so you can use highschool physics to calculate the number of electrons in an amp. 6.25x 10¹⁸ So basically that is not rate limiting, the only rate limiting problem is the transfer heat on the transfer pole and its effect on distal superconducting. Agreed that temperature is a problem, but if the Tmax can be improved with other metals and configurations, this offers a tremendous potential. Imagine three printers, one prints a layer of metal on the spool and the other prints a layer of graphene as it passes the other side of the spool, then a third prints a third layer of metal on the other side, and possibly a forth prints a thin layer of insulation say polyethylene, and you do this 50,000 times. . . . . . . . .

Some of the things one could do. Charge particle accelerators such as in an ion drive, imagine increasing the ISP to say 100,000 for xenon. Small size, not much heat generation, better ion control.

Space weapons, asteroid control. Mass accelerators (carbon widely available on asteroid, very close to the desired oxidation state). Space mail, package accelerators.

[K^2]

You've blown way past critical current. Keep in mind that it's current density, and not the absolute current in practice.

[PB666]

You've blown way past critical current. Keep in mind that it's current density, and not the absolute current in practice.

I thought i mentioned that, each graphene only need to be two hexagons wide, so you litterally have 4cm/1nm threads running in parallel as one sheet. Critical current is a function of the diameter of the conductor, this conductor is essentially flat. But lets just say you are right, just before going from hyperconductive to super conductive you split your graphene into a flat array of graphene threads. This could be done by essentially rolling the conductors into a spoll instead of using a bar to attach them. Of course 125 A of power is insane for a superconductor, but not farfetched, if the spools are mounted at 45 degrees to what is being accelated and the core is replaced by a magnet you could make the spool longer than a sewing machine spool to increases the number of threads, it really doesnt matter because graphene has a denity below 1 and so you are saving many fold over rare earths.

i dont know if you are correct about critical current and graphene, the problem is that with a large sheet if graphene ther is not one 4n+2 orbital, but an infinite number, and so you really have many with approximately basal potential energy orbitals for Electron waves to travel over, As long as dV is infinite on the terminals. This is one of those I wont worry about, graphene has a relatively low thermal stability, so its going to be a couple of decades before you see this be implimented as supermagnets in space, imho, they will work it out.

I thought I should explain this

1. suppose we have a single column of aromatic hexagons, we have a single 4n+2 orbital that connects one end to the next

2. if we add another hexagon any where we create 1 additional orbital, roughly the same potential energy.

3. If we add another hexagon anywhere we create 2 additional orbitals. If we keep doing this parallel to the first column of hexagons we create 2ⁿ orbitals were n is the length of the original length of the columns in hexagons. The number of equivalent orbitals should approximate (2^x)^(y-1)/2. Therefore if your transformer is say 50000 turns over 10cm/turn that is 5000 meters and the with two hexagons per nanometer that means you have therefore x = 5 x 10¹²Ã¢â‚¬â€¹ hexagons. If the width is 10⁸ hexagons so that there are around 10²⁰ orbitals to dump electrons into that coonect one end to the other, there are an infinite number of circuitous orbitals to dump electrons into, but the lowest energy orbitals are the orbitals that span the entire sheet, or close to the entire sheet.

I don't know if electrons will travel a circuitous route given infinite choices, by increasing the number of threads you would be greatly decreasing the number of lowest energy orbitals, so there might be a tradeoff by threading and doing so without verifying that the sheet width increases heating on the sheet. Uncertainty suggests that the field would be in all paths at once and in all orbitlas distributed according to potential energy.

I should also add that by spooling the sheet you a creating a field that is spiraling which in and of itself should create heat, and that the layering would create a good heat insulator......details.

Edited September 4, 2015 by PB666
explain

[AngelLestat]

That might work if you want micro batteries with micro capacity.

But if you want to enter to the 3d world where objects had more than 1 cm of thick, then your battery will skyrocket in cost, something that might be really pointless not matter its niche.

[PB666]

That might work if you want micro batteries with micro capacity.

But if you want to enter to the 3d world where objects had more than 1 cm of thick, then your battery will skyrocket in cost, something that might be really pointless not matter its niche.

The whole point of graphene, superconductivity and small was to make it light for use in space. Seriously, if you can reduce the size of something from half a cubic meter to 5 cubic cm do you really care if there if there is a 40K difference in the SC temp. Its small, your in space, a sun shield and a magnetic deflector and your outside temperature is almost there. And we can already use a two stage system that gets us there so .......

[AngelLestat]

But even space applications focus in cost.

If you need millions of those perfect printed or placed layers, the cost will rise so much, that it will be even pointless for space.

It can be usefull in the future with new manufacture techniques, they can make aerogel base on graphene oxide or graphene ink, which are 3d materials that are produced as a whole.. no stacking layers after layer.

[PB666]

But even space applications focus in cost.

If you need millions of those perfect printed or placed layers, the cost will rise so much, that it will be even pointless for space.

It can be usefull in the future with new manufacture techniques, they can make aerogel base on graphene oxide or graphene ink, which are 3d materials that are produced as a whole.. no stacking layers after layer.

Wait . . . . . . .this technology is improving very fast. If it took six months to make a part, not a problem, the typical space prep phases is 5 years to a decade anyway. The other thing is who needs 50,000 windings, its just an example, maybe 2000 would do. If you don't stack, graphene is of little use to you, because its flatness and stackability is one of its key property. When you see 4n+2 think flat, pancakes, 3D ink would have no better conductivity than graphite, you need sheets, long flat sheets.

[PB666]

http://gas2.org/2015/08/24/graphene-converts-heat-electricity/

Could increase power output of solar panels in space by placing it on the back side of solar panels, or on the heat radiators.

[PB666]

http://qubitsnews.com/2015/08/31/worlds-thinnest-light-bulb-created-from-graphene-2/

Now we have a graphene with LED like properties.

[Ralathon]

Yea yea, we get it. Graphene is amazing stuff. The problem is that we can't mass produce high quality sheets yet. The fact your smartphone doesn't have graphene batteries yet is the proof of that.

It is a very common joke that Graphene can do anything except leave the laboratory. Stop riding the hype train until someone figures out how to make large batches of the stuff.

[PB666]

Yea yea, we get it. Graphene is amazing stuff. The problem is that we can't mass produce high quality sheets yet. The fact your smartphone doesn't have graphene batteries yet is the proof of that.

It is a very common joke that Graphene can do anything except leave the laboratory. Stop riding the hype train until someone figures out how to make large batches of the stuff.

I haven't mentioned batteries yet. How long did it take for lithium ion batteries to go from first experiments to your cell phone. We are discussing fusion reacors as electric power supply for IS spacecraft and yet fusion reactors have been 20 years in the future since 1960. Bet graphene reaches the public before fusion power does.

[More Boosters]

I haven't mentioned batteries yet. How long did it take for lithium ion batteries to go from first experiments to your cell phone. We are discussing fusion reacors as electric power supply for IS spacecraft and yet fusion reactors have been 20 years in the future since 1960. Bet graphene reaches the public before fusion power does.

What exactly are the problems we currently face in making a fusion reactor anyway?