Surprising Superconduction in Plutonium

jihema writes "Dr Strangelove would have liked this : a plutonium compound turns out to be a superconductor at relatively high temperature (18 K). The magnetic properties of this metal make this fact rather unexpected and contradicts the accepted theory on superconduction."

Comments

Pb--Great

[Henry V .009]

Superconducting power lines would transmit electricity from power plants to homes without most of the energy loss that occurs now

Unless someone takes them down to build an atomic bomb!

Re:Pb--Great

[cryptor3]

Superconducting power lines would transmit electricity from power plants to homes without most of the energy loss that occurs now

...unless the temperature ever goes above freezing... for DRY ICE.

Re:Pb--Great

[capnjack41]

I don't think that's the point. I think they're just interested on what impact this has on superconductor theory. No one's about to build a huge radioactive train or a bunch of radioactive power lines.

This makes me wonder. I don't think the article really clarified on whether it was the radioactive property that makes it interesting, or just how the actual metal atom works. If that's the case, then what's the problem with depleted uranium? IANANP (nuke physicist), but I guess since they didn't mention it, it wouldn't work.

Re:Pb--Great

[Rick the Red]

IANANP either, so someone please explain just what "depleted uranium" is. If it's depleted, then it isn't uranium anymore, is it?

Also, depleted uranium isn't plutonium, so it's probably not superconducting. Sorry.

Re:Pb--Great

[mindstrm]

IT's a differnet isotope of uranium, and it's still radioactive, just not in the right way. IT's relatively safe, you can handle it, etcetera....
but when it gets blown to powder and ends up in the food/water supply, it's not good.

It's probably also highly toxic.
One of the major dangers of plutonium other than radioactivity is the fact that it is extremely toxic.;

Re:Pb--Great

[mmontour]

IANANP either, so someone please explain just what "depleted uranium" is. If it's depleted, then it isn't uranium anymore, is it?

It refers to the amount of the isotope with atomic weight 235. "Natural" uranium is mostly the 238 isotope, with (IIRC) about .07% of 235.

"Enriched" uranium has a higher ratio of U235, and "depleted" has a lower ratio. Weapons and some power plant designs require enriched uranium because it has different fission characteristics (e.g. the probability that a neutron will cause the nucleus to split).

Enriched, natural, and depleted uranium are chemically the same; plutonium is different.

Re:Pb--Great

[Henry V .009]

You idiot! Now all of the terrorists that I fooled into building their weapons of mass destruction out of lead will realize their mistake. I hope you understand that you'll be personally responsible when they nuke Dallas.

Re:Pb--Great

[BSOD from above]

I'll bring the beer...

"OK, lets freeze this plutonium,

[Unknown Poltroon]

and run high voltage through it"

Dosent this sound like some kind of bad b-move plot?? Im wating for the time traveling DeLorean to show up.

WHAT?!

[Hubert_Shrump]

You mean we were fitting rockets to those things for years, when all we needed was a great huge magnet?

Man, the Pentagon's going to be pissed.

Re:buying plutonium on the black market

[FeatureBug]

"this scares me" -- overrated scaremongering

The article clearly says the team was at Los Alamos National Laboratory. LANL has the authority for this type of work. Sarrao is not some random university professor. He works for LANL.

Is jihema drunk? 18 K is not warm at all.

[Inoshiro]

18 K is hardly a "low-temperature" superconductor. That temperature is around where helium finally becomes a liquid, which was where superconductor research was at the turn of the 19th to the 20th century. Nowadays, we have things like HTS material (bismuth-based, copper oxide ceramic) which will superconduct up to temperatures of 108 K! A far cry from 18 K.

For those metric impaired people in the audience, 108 K (aka -165 C) is -265 F. 18 K (aka -255 C) is - 427 F. HST composites only need liqud nitrogen (which costs the same as milk), rather then liquid helium (which is very, very, very expensive) to work.

Re:Is jihema drunk? 18 K is not warm at all.

[zero_offset]

Read the article.

18K is relatively warm compared to where they expected it would become superconductive (like 2K).

Though I'll grant that "18K" by itself doesn't make a good figure to quote for the /. submission.

18K is pretty warm given the circumstances..

[Tyrnagog]

All of the very high K superconductors (>100 K) are (IIRC) brittle ceramic compunds that could not be easily constructed into something of commercial use.

While Plutonium is "extremely radioactive and chemically toxic", it is just a base metal, not a compound. I am not to familiar with the metallic properties of Plutonium (malleability, brittleness, etc) but I would imagine that if one metal (even if it is trans-uranic) has high K properties like Plutonium, others may as well...

Re:18K is pretty warm given the circumstances..

[Sir Holo]

All of the very high K superconductors (>100 K) are (IIRC) brittle ceramic compunds that could not be easily constructed into something of commercial use.

Nope. They are easily constructed into something of commercial use. I work on the technology. It is just not cheaper than copper wire for power transmission (yet). Superconducting cables are, however, currently used in various specialized applications, and in 2004, a superconducting power transmission cable will be installed in the Northeast US. The Japanese and Germans are making great advances as well as the US. Although the superconductors are "brittle" ceramics, one can wind a superconducting cable around a bottle neck, and it will still work fine. Why? It's thin. If that doesn't explain it, consult basic mechanics of materials textbook.

Re:18K relatively warm?

[jerde]

Right. Okay. Go read the article! (This is the correct response to 90% of the posts in this thread)

18K is relatively warm compared to plain-old superconducting metals. When superconductivity was discovered in 1911 occurring in Mercury, later in other metals as well, it was at only a few degrees Kelvin. 18K is relatively warm compared to that.

Half a century later, in 1986, we found ceramic compounds that would superconduct at much much higher temperatures. Those compounds superconduct by a different process, so they're dubbed Type 2 superconductors. (as opposed to Type 1 for metalic elements)

The article doesn't say -- or they probably don't even know for sure -- what type of superconductivity was observed in Plutonium. Or if they were using pure elemental Plutonium or some compound that contained it.

And finally, lots of other comments here make fun of how "useful" Plutonium is. Duh. It's not:

The discovery has no immediate practical value but is important because it adds a new dimension to the study of superconductivity, Stewart said.

"You can't make practical materials out of something as radioactive and chemically poisonous as plutonium," he said, "but John Sarrao and this collaborative team have made a big leap in understanding superconductivity from a fundamental point of view."

Basically, it means that superconductivity is still not completely understood -- this uncovers yet another twist, and will help to develop the theories further.

Secrets of the universe stuff, you know.

- Peter

Re:Is jihema drunk? 18 K is not warm at all.

[rthille]

Read the article, it talked about superconductors at 138K...however, for materials you 'don't expect' to superconduct, they typically do superconduct, but at around 2-3K.

great new product for research budgets

[budalite]

Can anyone actually point me to a useful working product of superconductors, or holograms or nanotechnology ? Apparently, these things are the Holy Grail of Science. Methinks they are more like the Emperor's New Clothes.

Re:great new product for research budgets

[Steve S]

superconductors: MRI and SQUID (superconducting quantum interference) medical imaging.

nanotech: buckyballs - best lubricant out there, being composed of billions of nanoscopic ball shaped molecules. Potentially superstrong carbon structures, drug delivery systems, etc. nanotech is still in its infancy.

holograms: used to protect currency all over the world from forgery.

Re:great new product for research budgets

[budalite]

1. OK, are these things really using semiconductors in production units? If so, good!
2. Actually in a commercial product?
3. forgot about the holos on money. Ok, besides that! :) Still, not a whole lot of examples here. Wish it weren't true, but it is. Cheers, :})||

Re:great new product for research budgets

[nounderscores]

1 it would be impossible to get those kinds of intense magnetic fields without using superconductors. Conventional conductors would melt with the kind of electrical current you would need.

2 unfortunately buckyballs don't seem to lubricate. but see that post on FLIR made with nanotechnology for more commercial nanotech products.

3 You want great 3d uses of holograms? Try imaging This technique could generalise for anything else you want to look at under a microscope in 3D. Cells. Fuel rods in a nuke reactor. the hologram captures all that data at the quantum level.

the application is commercial because there are hologram companies that sell equipment to other companies. If you want to get into it yourself for next to nothing look at this link and search for hologram

Re:buying plutonium on the black market

[Mark of THE CITY]

The LAST thing one of these "random University professors" would do is buy Plutonium on the black market.

Of course; could you imagine putting this on a research grant?

Name: Plutonium
Qty: 100g
Vendor: mumble

:)

Liquid N2 vs Milk

[ShavenYak]

HST composites only need liqud nitrogen (which costs the same as milk)... ...but is nowhere near as much fun when worn as a mustache!

Got Severe Painful Frostbite?

Re:more info

[ShavenYak]

Somebody should get this guy together with the TimeCube guy.

Re:18K relatively warm?

[lommer]

All very interesting. I remember a huge debate here on /. a while ago where the big question was about the speed of electricity vs. the speed of light, and how the speed of electricity was normally only 2/3 that of light. Does this also hold true in superconductors? Or can they transmit electricity faster? Just curious.

Type I vs. Type II Superconductor

[DrLudicrous]

I am by far no expert in superconductivity, but I have worked with superconductive materials here and there. This discovery seems very similar to that of MgB2, which superconducts at about twice the temp, 37K or so. If I remember correctly, wasn't that a type-I superconductor? It seems to me that this plutonium-based superconductor (is it just pure Pu?) would be a classical BCS type-I superconductor. Most type-II's tend to be really complex as far as their constiutent elements numbers and ratios, e.g. YBCO. Plus, 18K is well below 37K, so in the regime of classical type-I Tc's. Also, I think that the cooper pairs are probably being formed by the valence f-orbital electrons. Maybe a theorist can show that this yields the lowest possible ground state energy. Besides, Yb of YBCO fame is also in the same group of elements as Pu who have partially filled f-orbitals.

Re:18K relatively warm?

[jerde]

According to this site, the "velocity of propagation" of signals in the blue pair in CAT5 cable is 66% that of "c", the true speed of light. (A few percent of that is because of the twists -- if you completely straightened out the individual wires, they'd stretch longer than the original length of the cable)

Of course there's the difference between the speed of one electron vs. the speed that voltage changes (i.e. information) travel along the wire.

According to this guy, the actual movement of electrons is VERY very slow through a normal wire, on the order of centimeters per hour.

What about superconductors?

I didn't have tons of luck Googling, but I found a message board posting that states that the electron drift rate is much higher in superconductors.

And then there's this physics Q&A about why electrons don't travel at actually the speed of light.

- Peter

Has been done!

[infolib]

In Copenhagen, students were recently allowed to purchase Two kilograms of weapons-grade uranium!

The students were part of a group that do experimental shows demonstrating funny/scary/fascinating physics. Apparently the guy who signed the list of wanted equipment didn't notice the uranium between the more boring stuff such as lasers etc.

Now we just need a seller. Any offers? (Yeah, I know, i should just mail press@uruklink.net and offer to keep it while there's inspectors around)

Expert?

[Old Wolf]

I just read this first page (Introduction to 231Pu universe etc) and it is the biggest load of crap I've seen since creationism. I'm surprised the Swedish government allows the association of its TLD with this junk.

Why do I say this? I read the page, and see this guy making his claims. Where's his evidence? I scroll down some more waiting for the exposition to end and the science to start. Hmm, still none, still just more guff saying how clever the guy thinks he is. Whoops, it's the bottom of the page. Perhaps he should rename his site 'tabloidphysics.se'.

And the actual source material: He didn't actually say what his theory was, but I glark that he thinks the universe is an atom of plutonium, and the Milky Way is one of its electrons. Now, riddle me this. The universe has more than 94 galaxies. So, unless I've just busted his theory, I guess I haven't read far enough to reach the section where he rubbishes observational astronomy?