A New Family of High-Temperature Superconductors

sciencehabit writes to let us know that physicists are hailing the discovery of a new type of superconductor as a "major advance." The new materials could solve the biggest mystery in condensed matter physics — i.e., how and why cuprate superconductors work — as well as paving the way for practical magnetic levitation and lossless transmission of energy. "God only knows where it will go," says one Nobel Laureate. After the discovery of superconductivity in an iron-and-arsenic compound at 26 kelvin, several Chinese research groups quickly found related materials that are superconducting up to 55K. (Cuprates go as high as 138K; liquid nitrogen boils at 77K.)

Background Information

[explosivejared (1186049)]

Here (PDF warning) [uni-augsburg.de] is an in depth look at high temperature superconductors, especially the cuprate families, for those not well versed in the subject.

Hope it fits in a bedroom

[4D6963 (933028)]

as well as paving the way for practical magnetic levitation

Awesome! Can't wait for my superconductor magnetic levitation bed!

Re:

[Vectronic (1221470)]

"...in an iron-and-arsenic compound..."

You might not wake up from that bed...lol

Re:

[evanbd (210358)]

You can levitate frogs and such by themselves, without having to support them on a levitating magnet -- see the Youtube video [youtube.com]. Of course, that technique doesn't work with superconductors -- the field strength required is higher than they can sustain. Instead, you need a 6 megawatt electromagnet [hfml.ru.nl].

I suppose 6 MW to levitate a frog is about as impractical as it gets...

Re:

[compro01 (777531)]

i wonder, how does the magnetic field needed scale with the mass to be levitated?

Levitation

[HTH NE1 (675604)]

as well as paving the way for practical magnetic levitation

Just let me know when I don't need to have my feet frozen to my hoverboard to make it work.

Superconducting Supercomputers?

[Doc Ruby (173196)]

Are these "not so low" temperature superconductors usable to make semiconductors for computers? Can such a superconducting computer be run at extremely high clock rates, or just extremely low circuit latency, to make really fast computers not limited by the heat inefficiencies of today's regular computer chemistry?

If so, how about building these computers buried in Antarctic ice? Winter air temperature drops to -80C; deep in the ice it's probably even lower. 138K is -211C. So the energy required to cool the

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[timeOday (582209)]

I am waiting with interest for an informed response to your question. But my guess is that a superconductor is only half of a supersemiconductor, which is the name I just made up for something that's instantly switchable from 0 to infinite resistance. And since infinite resistance is impossible, I would guess there will still be some current leaking through any real semiconductor, and thus waste heat. Besides the direct loss of this heat, it would make it harder to keep the superconducting parts cold en

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[Jerf (17166)]

The problem is what to do with the heat pumped out, which could damage the arctic nearby, maybe even melt the foundation. But if the total mass cooled is small (like a few dozen microchips), that byproduct heat could be used to keep some human operators alive.

Scale, scale, scale, scale, scale. Don't let environmentalist mottos fool you; humans aren't actually "heating" the planet. By pumping large amounts of a greenhouse gas into the atmosphere, we are causing the planet to retain more heat. (This isn't new

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[FailedTheTuringTest (937776)]

The poster was talking about local heating effects, not global, and while you're right that a few computers won't create a heat island and change the local ecology, there is one sort of local effect that is quite real and well-known all across the Arctic. Any warm structure will heat the ground it is built on slightly, and in the high Arctic where permafrost [wikipedia.org] exists, anything you build (including all buildings and pipelines) has to take this into account or the permafrost melts and the structure sinks. The

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[ispeters (621097)]

I don't really have a lot to say, but you made one error. Zero degrees C is 273K, so 138K is actually -135 degrees C, not -211.

Ian

Re:Hot!

[Ctrl-Z (28806)]

The "firestorm" was ignited by the discovery of cuprate semiconductors, which "have critical temperatures in excess of 90 kelvin"[1], which is above the temperature of liquid nitrogen.

[1]http://en.wikipedia.org/wiki/Superconductor [wikipedia.org]

Re:Hot!

[explosivejared (1186049)]

The article specifically mentions 138 kelvins as the highest temperature where cuprates still hold on to superconductivity. That's roughly -115 degrees celsius. This greatly increases the viability of the material by greatly reducing the energy required to hold it at a critical temperature. Think about the wide extent to which liquid nitrogen is used.

Currently we are in the stage of trying to understand just what exactly is going on at the particle level. Once we move past this research stage (disclaimer: it's been going on for twenty years), the possibilities these materials provide are pretty much endless.

Re:Hot!

[DieByWire (744043)]

The article specifically mentions 138 kelvins as the highest temperature where cuprates still hold on to superconductivity. That's roughly -115 degrees celsius.

I believe you mean -135 degrees celsius.

That last twenty degrees is what keeps Minnesota from superconducting in winter.

Re:

[Rei (128717)]

The big deal with this discovery isn't that the possibilities the new materials they've found are endless. They actually underperform what we already have. It's that we don't understand how what we have (cuprate superconductors) works, but if we did, we could potentially find much higher-temperature superconductors. This gives us a key to help understand high temperature superconductivity. And the possibilities of high-temperature superconductors would be endless (assuming they could be made affordably).

Re:Hot!

[jellomizer (103300)]

Well there is a huge difference in the price for using Liquid Nitrogin vs. Liquid Helium. Right now for superconductors used in MRI's they use Liquid Helium at 4k. And they use Liquid Nitrogin as an insolator to protect caseing from cracking. At roughly $1000.00 per leter of Liquid He, Liquid Nitrogin is much cheaper. Anf if they can get to a point where you can maintain superconductivity at Dry Ice level it would cause far more advances in society.

Re:Hot!

[evanbd (210358)]

Where do you get $1k/L? A quick google search turns up $3-5 per liter, which is about what I recalled. LN2, of course, is much cheaper -- $0.25 in small quantities, $0.05 per liter or less in very large quantities.

Dry ice is more expensive than LN2, because you have to pay for the CO2, rather than just liquefying air. But if you don't actually need dry ice, then dry ice temps are certainly cheaper to reach than LN2 temps.

Re:Hot!

[nmos (25822)]

Where do you get $1k/L? A quick google search turns up $3-5 per liter

Well duh! He's talking about MEDICAL liquid HE which is obviously much more expensive than normal liquid HE. Ever get a bandaid put on at a hospital?

Re:Hot!

[krlynch (158571)]

At roughly $1000.00 per leter of Liquid He, Liquid Nitrogin is much cheaper.

You've got the right idea, but your numbers are a bit out of whack ... LN2 is about $0.10/L in large quantity, while LHe is about $3-20/L, with large variation in price around the world (due to constrained supply and large transportation and energy costs). US He is relatively cheap, as we have a few of the small number of high quality sources. In Europe, He is very much more expensive, as they don't have any local, high quality sources. A recent compilation of costs is available here: http://hypertextbook.com/facts/2007/NadyaDillon.shtml [hypertextbook.com]

Helium is so expensive, because it is very entery intensive to liquify, and it isn't commercially extracted from the atmosphere like nitrogen ... there just isn't enough of it to be commercially viable. Instead, it is generally found in pockets underground and "mined". The helium originates as alpha particles in the decay of radioisotopes (mostly Uranium and Thorium), and permeates through the crust. It gets trapped in high pressure gas pockets by impermeable rocks, in the same types of geology that trap natural gas, and is extracted for commercial scale from those pockets. There are only a few global sources where the concentrations of helium are high enough to extract economically.

Liquid Neon as a refrigerant

[billstewart (78916)]

Most gasses have boiling points higher than nitrogen's, but there's at least one option between cheap liquid nitrogen and expensive liquid helium, which is liquid Neon [wikipedia.org], which boils at 24.5 kelvin. The Wikipedia article says it's not cheap, but not as expensive as liquid helium, has better refrigeration properties, and is extracted from air rather than rare sources that risk exhaustion.

Re:

[David Gerard (12369)]

All these new materials are ridiculously brittle and difficult to form ceramics, so making coils and so forth is a major PITA and helium actually works out cheaper in practice.

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[Agripa (139780)]

There are superconductors that work above the boiling point of nitrogen though right? Why not use those instead? Do the cost/problems offset the saving in coolant?

My understanding is that their lack of malleability as well as their very low critical current density prevents large scale use.

http://en.wikipedia.org/wiki/YBCO [wikipedia.org]

liquid nitrogen 77K is the goal

[spineboy (22918)]

A big goal is to get superconductors to work at 77K, because then they can be cooled by cheap liquid nitrogen. Lower than that, you have to use liquid helium(I think) which is quite expensive.

Re:Hot!

[ThreeGigs (239452)]

The excitement isn't about superconductivity at 55K by itself. It's got everyone excited because, *finally*, there's something besides cuprates that superconducts above about 33K (which defines high temperature in the superconductor world).

Now, instead of having just one 'family' of HTSC materials to base hypotheses and theories upon, scientists now have TWO. Now they can compare similarities and differences between those two families. This gives them a HUGE boost towards figuring out the exact mechanism involved, plus potential leads on new materials that exhibit similar atomic structure which could also superconduct.

Very Hot!

[l2718 (514756)]

1. "High T_c" is a technical term. Indeed, 55 kelvin is "high" (though not as high as the record for cuprates). You have to compare it with the typical T_c for metals (a few kelvin). The difference is between liquid helium temperatures and liquid nitrogen temperatures (which cuprates have reached already and perhaps the new compounds also will).

2. More improtantly, this will ignite a "firestorm of research". You see, we don't have a good model of high T_c superconductivity (unlike the BCS [wikipedia.org] model for metals). Having several different superconducting systems will help theorists isolate the significant features of the system from the less significant ones.

3. Seeing superconductivity in a totally new material is exciting. This is interesting basic research even if today we dont' have a practical application. If we don't do the research we'll never get to the practical stage.

There's already practical implementations...

[Firethorn (177587)]

I know of at least 5 superconductor power lines installed in the USA.

The important point was getting over 77k, where the relatively cheap liquid nitrogen can be used instead of other things like liquid helium.

Re:

[Smidge204 (605297)]

I recall something in the news about a HTS cable being installed in Albany, NY in... 2006? IIRC it wasn't especially impressive - a single cable that shunted power between substations several blocks away.

I'm not aware of any others and would also love to hear about them.
=Smidge=

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[Firethorn (177587)]

There's 3 in Chicago that replaced either 7 or 11 oil cooled copper lines. The power company actually made money on that while increasing capacity I hear. They pulled out and sold the copper to cover the cost of the conductors. The LN cost is covered by reduced heat losses and the elimination of the need to pump & cool the oil.

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[bperkins (12056)]

looks a bit too low for "practical" implementation yet.

At this point people are more interested in the physics rather than the practical applications.

This discovery is pretty important, because as TFA says, the exact mechanism that allows high temperature superconductivity to occur isn't widely agreed upon. Another system to study makes it much more likely that theorists will agree on exactly how this works.

Re:US science is dying?

[peragrin (659227)]

If you think China is a poor third world country then you are going to be shocked.
China is mostly a second world country, isn't very poor(the USA is spending trillions there), currently is almost able to duplicate just about every technologically advanced device being built.

there was a chinese company called NEC which duplicated the Real NEC's tv's poorly but close enough to work for several years before they got caught.

While it will be another 5-10 years China is rapidly building up technology, science, and math. They have the manpower power and will, just like japan had 30 years ago. Remember 40 years ago the Japanese only made junk, 20 years later they owned the electronics market, and 10 years after that had some of the best selling cars out there.

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[Digi-John (692918)]

there was a chinese company called NEC which duplicated the Real NEC's tv's poorly but close enough to work for several years before they got caught.

Not only did they make the TVs, but apparently they also dealt with real NEC plants on a regular basis, and due to poor organization, nobody caught on.

Re:

[Anpheus (908711)]

If I recall, they didn't just go so far as to imitate NEC, but even had their own infrastructure set up, and their own R&D set up to allow them to offer devices that the real NEC never did.

Re:US science is dying?

[by Anonymous Coward]

If you think China is a poor third world country then you are going to be shocked.
China is mostly a second world country

"First world", "second world", and "third world" are not some ranking of affluence. "X world country" was an old Cold War term. First world nations were those aligned with the West. Second world nations were those aligned with the Soviets. Third world nations were those aligned with neither. Since the fall of the USSR, there is no longer such thing as a second world country.

Third world countries tended to be poor and underdeveloped. Now "third world" has become synonymous with "poor", but it is really a misnomer.

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[smoker2 (750216)]

No, actually third world is the only correct usage of the group. The other 2 are Old World (Eurasia) and New World (The Americas).
Third world is so named because it is neither of the other two.

Re:

[Hucko (998827)]

Australia is a third world country??? eep!

Re:US science is dying?

[What Would NPH Do (1274934)]

I am more interested as to why American scientists weren't the first in on this,

Because despite the jingoist tune, the US hasn't been the forefront of technology and science for quite some time. When you have creationists trying to ruin science education all across the country it's not that surprising.

and why such cutting-edge research is being done in China (a poor third-world country).

China is poor? Since when? They're raking in the dough which is why they also hold 1/3 of the US national debt. Besides, countries in Southeast Asia have been pumping out cutting edge research for years now. If you were to shed the chauvinism for a few hours you might have noticed this already.

Re:

[megaditto (982598)]

Sure has. US is number one, see here: [nsf.gov]

The United States has the largest share of all internationally authored papers of any single country, and its researchers collaborate with counterparts in more countries than do the researchers of any other country.
U.S.-based authors were represented in 44% of all internationally coauthored articles in 2003 and collaborated with authors in 172 of the 192 countries that had any internationally coauthored articles in 2003.

And here: [in-cites.com]
US ranked #1 at 3 times the number of pape

Re:US science is dying?

[timeOday (582209)]

Let me first say, the idea of US science "dying" is just silly. And yes, for the moment we are leading.

Hanging on to our lead, on the other hand, is doubtful [scidev.net]: "Cited papers first-authored by Chinese scientists -- an important indicator of scientific creativity -- increased by 25.3 per cent in 2006, and the number of times they were cited increased 28.3 per cent. However, China remains thirteenth in terms of total citation numbers." At that rate, China won't be in 13th for long.

From the global perspective it doesn't matter; all this means mankind as a whole is simply progressing much faster now. But from the US nationalist perspective, this definitely decreases our ability to compete for increasingly scarce natural resources. We've already seen this occur drastically in the price of oil.

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[MrNaz (730548)]

In the immortal words of Homer Simpson: A little from column A, and a little from column B.

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[Slime-dogg (120473)]

When you have creationists trying to ruin science education all across the country it's not that surprising.

This is a red herring.

I would chalk the lack of advancement up to the lack of need for it. We can point and say, "well, we do need this," but there is no sense of urgency to that need.

Performance happens when pressure is applied. Some societies have instilled within themselves a constant pressure, and apparently progress at a faster rate than others. I imagine that the lack of urgency and impending need is what negates motivation. It doesn't seem like this applies only to scientific research, eith

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[megaditto (982598)]

Foreign-born scientists. There's a big difference here since it doesn't actually matter where they were born so long as they work for us now.

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[Artuir (1226648)]

This is assuming standard pressure, of course. Any advancement in the operating temperature of a superconductor would make it easier to pressurize a system in order to bring its operating temperature up.

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[Molochi (555357)]

I've always been under the impression that a major reason for superconductor research was to raise the operating temperature to a point where parity (or better) was reached between maintaining a magnetic bottle and the energy gained by a contained hydrogen fusion reaction. I'm guessing that the lack of posts stating "Mr Fusion to be trial-ed this fall" means that liquid nitrogen is too energy-expensive to make this a reality.

Re:Is this really news?

[Andy Dodd (701)]

It is news not because of any new temperature records, but because of the fact that these are the first superconductors outside of the cuprate family to exhibit high critical temperatures.

This is an entirely new family from the cuprates. The cuprates started much lower too. Also, even if this family never compares to the cuprates in performance, the behavior of this new family could shed light on the (relatively unknown) mechanisms of cuprate superconductivity, allowing for that family to be developed further.

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[somersault (912633)]

Yeah, how are we going to 'fend for ourselves' without superconductors? :O

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[the_humeister (922869)]

And we know democracies never lie either. What's your point?

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[Smidge204 (605297)]

Because that was nanoparticles (~40 atoms each), not a solid material. Even if the electrical resistance within the particle was perfect, the resistance from one particle to the next could not be guaranteed.

Last month some team in Germany discovered a "room temperature" superconductor. That's still not terribly useful, though, unless you can build a wire that is safely under almost 4000 atmospheres of pressure required to turn the Silane gas into a solid.
=Smidge=

Re:

[Ceriel Nosforit (682174)]

It's a misquote BTW, taking the whole thing out of context. The full quote is:

"If it's really a new mechanism, God knows where it will go," he says.

One must at the very least indicate that it is a partial quote, like so:

"...God knows where it will go."

The "..." indicates that the first part has been cut off.

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[nmos (25822)]

In fairness most proposals for perpetual motion machines (actually all that I've seen) actually claim decreasing entropy, not just zero change. IANAP but I do wonder if superconductivity will turn out not to be completely lossless but just very very nearly lossless. Of course, in practice we're not talking about closed systems anyway.

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[exploder (196936)]

Are you sure there is a voltage gradient across a superconducting transmission line?