High Temperature Superconductivity Record Smashed by Sulphur Hydride

https://medium.com/the-physics-arxiv-blog/high-temperature-superconductivity-record-smashed-by-sulphur-hydride-c853795079bb

by jonbaer • 12 years ago

118 34 12 years ago

medium.com

ableal• 12 years ago

"[...] have measured sulphur hydride superconducting at a temperature of 190 Kelvin (-83 degrees Celsius). There is a caveat, of course. The material has to be squeezed at pressures greater than 150 gigapascals — that’s about half the pressure at the centre of the Earth."

And 1.5 million times the atmospheric pressure at sea level ...

colechristensen• 12 years ago

Put in a different, less unreachable comparison, the yield strength of kevlar is 3.6 GPa (tension) and diamond forms between 4.5 and 6 GPa, w (compression)

It's been 60 years since we first synthesized diamonds, and back then they were capable of generating 10 GPa, that's only a factor of 15.

akiselev• 12 years ago

Another comparison: the highest pressure we can create without shock waves is 300-400 GPa with a diamond anvil cell [1]. With shock waves we can create momentary bursts of up to 100 TPa

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

throwaway_yy2Di3• 12 years ago

Tangentially, the metallic hydrogen mentioned is one of the craziest chemical substances to possibly-exist [0].

Besides likely being a room-temperature superconductor (at ridiculous pressures, like 500 GPa), it's postulated to be metastable -- like diamond, you could create it at pressure, and it might stay a solid metal at STP conditions. It's postulated to be made of atomic hydrogen -- lone H atoms, without the molecular bonds of H_2. The recombination energy H + H -> H_2 suggests [1] it's the most energy-dense chemical fuel that exists, with 20 times the specific energy of {H2 + O2}. It could allow [1] rocket engines with I_sp of 1,700 seconds -- four times higher than LH2/LOX. It's thought to be the main phase of hydrogen inside the planet Jupiter [2] and responsible for its dynamo [3] (but as an ordinary conductor, not a superconductor). It's also speculatively a structural material, one that's less dense than water [4].

It might have been created in a lab, in 2011 [4], but it's not clear.

[0] https://en.wikipedia.org/wiki/Metallic_hydrogen

[1] http://www.nasa.gov/pdf/637123main_Silvera_Presentation.pdf

[2] https://en.wikipedia.org/wiki/Jupiter#Internal_structure

[3] https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter

[4] http://www.nature.com/news/metallic-hydrogen-hard-pressed-1....

ajuc• 12 years ago

Wow, this reads like technobable from bad sci-fi :) I mean too good to be true kind.

aqme28• 12 years ago

Wow, I never considered the concept of a planet with a superconducting dynamo. That's a fascinating possibility.

throwaway_yy2Di3• 12 years ago

Even cooler: there's articles that claim the interiors of neutron stars are superconducting -- the current carried by proton pairs, rather than electron pairs. Maybe this is the source of magnetar dynamos.

http://www.ohio.edu/research/communications/neutronstar.cfm

https://en.wikipedia.org/wiki/Magnetar#Origins_of_magnetic_f...

Xcelerate5• 12 years ago

The metastability at STP is particularly intriguing. I wonder what quantum chemistry calculations have been performed on this material. I need to look this up, and maybe perform a few of my own!

Supposing that we can actually generate enough pressure to generate metallic hydrogen at some point, I wonder what the downsides of the material would be.

saalweachter• 12 years ago

It causes cancer in rats.

throwaway_yy2Di3• 12 years ago

That sounds like a fun weekend hack.

542458• 12 years ago

the downsides of the material would be

Well, considering how energy-dense it is... As a construction material, wouldn't it be more than a tad dangerous if it ever caught on fire?

tfgg3• 12 years ago

You might find a few of these papers interesting. The first challenge is working out the favoured crystal structure, including quantum corrections for the nuclear motion:

http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.184...

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.110...

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112...

ChuckMcM2• 12 years ago

If it were stable at STP it would make for a hell of an explosive. Simply cracking a small piece and blam! Instant over pressure and frost bite as the phase changed sucks all that energy out of the surrounding environment.

yxhuvud• 12 years ago

Well, the frost bite might end when the hydrogen meet some oxygen.

perlgeek• 12 years ago

When I studied physics five years ago, my impression was that nobody really understood high-temperature superconductivity.

There were some mathematical models, and some professors who claimed to understand it, but nobody was able to give a coherent explanation to the (mostly nearly finished) students, much less predict which materials would exhibit hight-temp superconductivity.

Does anybody know if that changed significantly? The article reads as though the measurements were inspired by the theory, which is always a good sign.

bradleyjg• 12 years ago

Although this is a high-temperature superconductor in the literal sense, it isn't the kind of high-temperature superconductor that no one understands. Those are the cuprates (and now iron based exotica).

What's really interesting about this potential discovery isn't just that it exhibits superconductivity at a relatively high temperature but that it seems to be a conventional superconductor. That should give some insight that a slightly better cuprate might not.

marcosdumay• 12 years ago

That's a type I (low temperature) superconductor. This type is well understood, and explaining in lots of introduction to materials science and quantum mechanics books.

High temperature supercondutors are still not understood.

jlarocco• 12 years ago

Completely off topic, but I really hate articles where all I initially see is a headline and a large, unrelated image.

I hope the trend dies quickly...

bainsfather• 12 years ago

This article is science writing done right.

All the information is there, but written clearly, without much jargon. A layman could understand it well enough, a physicist can understand it as well (the 'detailed' information hasn't been deleted or mangled by a journalist not understanding what they're writing, just presented clearly). And the graphs they show actually tell you what you want to know. Fantastic.

TheOtherHobbes• 12 years ago

Yes, it's very, very good - a joy to read.

High Temperature Superconductivity Record Smashed by Sulphur Hydride

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