Superconductivity near room temperature

https://www.nature.com/articles/d41586-019-01583-y

by Elof • 7 years ago

164 66 7 years ago

ttsda• 7 years ago

At pressures a million times those experienced on earth. Still an advance, of course.

saagarjha• 7 years ago

Also, the temperature (250 K, -23°C) is a bit chilly to be called “room temperature”. Still, this means you don’t need liquid nitrogen for cooling: a good but standard refrigeration system would be enough (and their insane diamond pressure apparatus, of course).

maxxxxx2• 7 years ago

Isn’t nitrogen cooling much easier to achieve than this level of pressure?

skunkworker• 7 years ago

This.

lanthanum hydride @ 250K at > 1 million atm.

It's still very impressive though.

Zanni• 7 years ago

Nobody wants "high temperature" superconductors. They want superconductors at roughly standard temperature and pressure. This is only an advance by the extremely artificial metric of considering temperature only. Ceramic superconductors work at liquid nitrogen temperatures and standard pressure, which is much more accessible.

I'm not raging at ttsda. It is an advance. Of sorts. But not nearly as much as the headline suggests.

hoseja• 7 years ago

I thought "high temperature", when talking about superconductors, basically means any temperature above the boiling point of nitrogen...

jeffwass• 7 years ago

The headline is accurate.

In the scientific community, High-Tc superconductors typically refer to Type II superconductors, eg cuprates. And the “High-Tc” term means above temperatures relative to the usual elemental superconductor Tc’s, eg about 20K or so.

Materials that can superconduct above 77K are especially sought after since they can be cooled with only liquid nitrogen, much cheaper and abundant than liquid helium.

gaze• 7 years ago

You’re vastly underestimating what the significance of what this is part of. High Tc superconductivity was thought to be essentially dead. Extremely few significant new results for decades. Now this and magic angle twisted graphene and some other stuff. It’s really really cool. It’s like we’re watching an entire field thawing and lurching forward.

deelowe• 7 years ago

What's wrong with high pressure superconductors? At least those don't require constant energy input, which would seem to be an improvement.

irq-1• 7 years ago

This is addressed in the second to last paragraph:

The effort to manufacture synthetic diamond provided substantial motivation for the development of high-pressure methods. Today, however, synthetic diamonds are grown using a low-pressure technique called chemical-vapour deposition. Optimistically, it might eventually be possible to use similar low-pressure methods to produce metastable superconducting compounds that are initially discovered at high pressure.

marcosdumay• 7 years ago

The maximum current and magnetic field you can apply to a supercondutor correlates very well with Tc, and it is likely that they are intrinsically linked so this correlation is unavoidable.

So, no, everybody cares about high temperature superconducors, because the higher the temperature, the strongest magnet you can build out of them.

baq• 7 years ago

this made me think, is the earth core a superconductor?

effie• 7 years ago

Interesting idea. It would help to explain persistence of Earth's magnetic field.

MichaelApproved• 7 years ago

No. The core has pressure but it's way too hot to achieve super conductivity.

taneq• 7 years ago

Technically correct. The most annoying kind of correct.

bhaak• 7 years ago

From a scientific standpoint, these results suggest that we might be entering a transition from discovering superconductors by empirical rules, intuition or luck to being guided by concrete theoretical predictions.

That would be an exciting development.

PuffinBlue• 7 years ago

The interesting thing about this is that the work neatly fitted with existing theory:

Drozdov et al. observed this isotope effect and found that, compared with the lanthanum hydride samples, the critical temperature in lanthanum deuteride samples is lower by almost exactly the amount predicted by the theory.

So like the article points out:

From a scientific standpoint, these results suggest that we might be entering a transition from discovering superconductors by empirical rules, intuition or luck to being guided by concrete theoretical predictions.

Whilst this result might require huge pressures, steady progress towards a theory of super-conduction is an exciting thing indeed.

tigershark• 7 years ago

Also it may open the road to find metastable material at room temperature, although I don’t think that it’s the case for lantanium hydride.

djaque• 7 years ago

I wouldn't be too optimistic. The theory they are talking about is BCS theory. Most of the other high TC superconductors cannot be explained with it and high TC BCS superconductivity so far requires crazy environments with no clear path to making them easier to use. With the kinds of pressures required to make this happen, it's probably easier to just buy liquid nitrogen and use other materials.

chiefalchemist2• 7 years ago

"Materials known as superconductors transmit electrical energy with 100% efficiency."

What is the level of (in)efficieny for say power lines? And power cords, etc around the office/house?

That is, of the electricity produced, how much is lost due to how it's transported? Does decentralizing production (e.g., solar panels on your own roof) help in any way?

jacquesm• 7 years ago

Smaller than or equal to about 1 percent is fairly normal for high voltage lines, lower voltage lines carry more current for a given amount of power and will experience higher losses.

skosch• 7 years ago

The bit of heat produced in a power line isn't a huge deal. The more important applications will be in electronics and electromagnets. For instance, it would make nuclear fusion reactors cheaper and easier to build.

atupis• 7 years ago

Also batteries https://en.wikipedia.org/wiki/Superconducting_magnetic_energ...

chiefalchemist2• 7 years ago

So this isn't about advancing scale and distribution, it's at the end product and product sub-component level. Good to know.

ben_w• 7 years ago

The inefficiency/losses depends on the distance, the voltage, and a few other things. In practice, losses are about 5% in the USA.

https://en.m.wikipedia.org/wiki/Electric_power_transmission#...

Faark• 7 years ago

US grid: losses are 5%. EU grid was in the same ballpark. The wiki page [0] is the source and was pretty much the best summary i could find when i was looking for it a while back. I'd love to read better material about it. Btw, losses seem to include theft. Wonder if much of a thing that still is.

In general, losses are estimated from the discrepancy between power produced (as reported by power plants) and power sold to the end customers

[0] https://en.wikipedia.org/wiki/Electric_power_transmission#Lo...

TrevorJ• 7 years ago

wow, that's way better than I would have imagined.

sfasfsafd5• 7 years ago

Insignificant: EEs can lower the losses by increasing the line voltage [0], at the expense of other challenges (namely taller pylons). It's about 5% over the length of the line.

Consider the other losses:

- Thermal (gas turbine) cycle: 40-60% lost (the big one) - Transformer loss: 1-2%. You pay this every time you step up/down, so it adds up. - Capacitive coupling: I dunno, but length dependent. It has to be about the same as Ohmic losses since once it's large you switch to DC lines (and take an Ohmic loss hit from lower V) - You're house's power factor (which, unlike industrial users, you're not charged for).

[0] in the sixties very large V lines were introduced (0.75 - 1.0 MV ??). They work, but it's not considered worthwhile.

sfasfsafd5• 7 years ago

Also, super conductors are limited by the amount of magnetic field, and therefore current they can carry [0] (above that limit they become normal conductors). Lowering T bellow Tc, increasing P increases the amount of current you can carry.

Point is, they're kinda useless for transmission.

[0] MRI magnets are superconducting for the efficiency of superconductors, not for the field strength! The strongest magnets are not made of superconductors but out of copper pipes: electrical conductors with coolant pumped through them!

oh_teh_meows• 7 years ago

I understand that the achievement in question was made in a high pressure environment; but if we get room temperature superconductors (at standard atm pressure), does that mean large scale hover cars/boards deployment will be viable as well [0]?

[0] https://youtu.be/PXHczjOg06w

wolfram74• 7 years ago

Room temperature super conductors are in the category of materials that will cause semi-magical transformations in society along side generation techniques that make .001$/KwH electricity, 1$/kwh electricity storage, or >200 gigaPa tensile strength materials for cheap.

adrianN2• 7 years ago

It depends on how much it costs.

trebligdivad• 7 years ago

What's the highest pressure that can be achieved over a useful (1 meter?) distance? I find it amazing that they managed to scale up cryostats to 1km for superconducting powercables at low temperatures - it would just be interesting if they started scaling up high pressure environments.

acd• 7 years ago

Is the Sun a superconductor? The Sun consist of a high percentage of hydrogen ~73% and there must be really high pressure at the center.

The suns central pressure is 2.5*10^11 bar according to nasa.

https://en.m.wikipedia.org/wiki/Sun

https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html

skykooler• 7 years ago

The sun is also at a temperature of millions of degrees. At these temperatures, there is no such thing as chemical bonds, and so the rules with hydrogen from the article don't apply.

agumonkey3• 7 years ago

interesting, is this a sub-field of physics ? high temperature physics or something ?

Nano2rad• 7 years ago

Maybe some properties of stars could be explained by superconductivity.

adrianN2• 7 years ago

How about the metallic hydrogen that might exist at Jupiter's core?

00N8• 7 years ago

it's probably too hot in there, but I wondered the same thing

madhadron• 7 years ago

No, it's a plasma. The high pressure in the article is a way of getting to a part of the phase diagram of that particular crystal where the superconducting transition happens at a higher temperature.

gwbas1c• 7 years ago

lanthanum hydride compounds become superconducting at 250 K

That's about -10F, or -23C.

(And it would make a lot more sense to put that in the article. Most of us don't "think" in Kelvin.)

penagwin• 7 years ago

Oh thanks!

Especially since the article says room temperature. I know a lot of people on HN are interested in superconductors but don't necessarily use K frequently if ever.

alkonaut• 7 years ago

That’s regular outdoor temperature in a lot of places. I wonder if there is any type of tech that is used in cold climates (or more on cold days) that would benefit from superconductors so they become more efficient when it’s most needed?

Oh - it has to be at 1atm and -20 of course...

nine_k• 7 years ago

It's easy: "room temperature" is about 300K.

apo• 7 years ago

Writing in Nature, Drozdov et al.1 report several key results that confirm that, when compressed to pressures of more than one million times Earth’s atmospheric pressure, lanthanum hydride compounds become superconducting at 250 K — a higher temperature than for any other known material.

One million atmospheres is an important detail to leave out of the title.

yo1• 7 years ago

Has this been discussed here? Navy files for patent on room-temperature superconductor.

https://phys.org/news/2019-02-navy-patent-room-temperature-s...

"The application claims that a room-temperature superconductor can be built using a wire with an insulator core and an aluminum PZT (lead zirconate titanate) coating deposited by vacuum evaporation with a thickness of the London penetration depth and polarized after deposition.

An electromagnetic coil is circumferentially positioned around the coating such that when the coil is activated with a pulsed current, a non-linear vibration is induced, enabling room temperature superconductivity.

"This concept enables the transmission of electrical power without any losses and exhibits optimal thermal management (no heat dissipation)," according to the patent document, "which leads to the design and development of novel energy generation and harvesting devices with enormous benefits to civilization.""

Superconductivity near room temperature

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