March 17, 2008

Superconductivity seen at up to 185K

On rare cold days in Antarctica this material would be superconducting outdoors without added cooling.

UPDATE: Announcement of room temperature superconductors from highly compressed silicon and hydrogen was premature in journal Science by Saskatchewan, Canada and German researchers. The transition temperature was low for the data that they had but they believe there is pressure zone that performs better

There are hints of superconductivity at 200K for aluminum nanoclusters. Not all three requirements for superconductivity confirmation are met. Plus the nanoclusters are of limited practical use. If confirmed maybe some kind of suspension or nanoparticle structure could be used. There have been million nanoparticle structures into a 3 dimensional form put together with DNA to form new crystals.

Another update, a new family of high temperature superconductors has been found and they are iron and arsenic compounds.

Common laboratory freezers can reach -85C or -86C. The superconductor is working at -87C.
Low temperature freezers for about $6000-15000.

Superconductors that would work at room temperature or with cheaper refridgeration and that can be produced in large volumes would revolutionize energy distribution and could improve all kinds of technology.

Like the 181K superconductor reported in January of 2008, the 185K superconductor appeared as a minority phase in a 1223/1212 host that was doped with extra Tm and Cu (see structure types at page bottom).
Through trail and error Tc was found to peak with slightly more Lead and slightly less Indium than the 181K formulation. Eight separate tests of the compound (Sn1.0Pb0.5In0.5)Ba4Tm5Cu7O20+ produced an average Tc of 185.6K. Interestingly, the 3-to-1 ratio of 4A to 3A metals in the insulating layer is also the ratio that produces the highest transition temperatures among binary alloy superconductors.

The discover of the new proposed record high Tc material is Joe Eck, the author of

In October of 2007, superconductivity near 175K was detected at ambient pressure in an Sn-In-Tm intergrowth. By doping roughly 28% of the Sn atomic sites of that molecule with Pb, Tc is increased further to 181K (183K magnetic). The revised chemical formula thus becomes (Sn1.0Pb0.4In0.6)Ba4Tm5Cu7O20+ with a 1245/1212 (non-stoichiometric) structure.

The report on the 175K superconductor discovery is here.

Other superconductor news

Thermo scientific makes and sells advanced freezer systems able to handle -196C

A 4 page pdf discussing the advances in cooling technology


Lobo7922 said...

Awesome, so this is finally going to happen, and in my frame of life time! 0_0
I have to say that I think this wasnt going to happen ever.

bw said...

Even bigger is the huge announcement in the journal science of room temperature superconductors from highly compressed silicon and hydrogen.

Lamont B Dumont said...

I've worked in a lot of labs, but I've yet to have a freezer that could hit -85C. I had a re-circulating chiller once that could get close to -80C. I've jockeyed a few viscosity baths that could hold -65F (-54C). Yes, -85C is positively tropical for superconducting. (People in Chicago are still wearing shots at that temperature, maybe thinking about garbbing a sweatshirt.) But lets not kid ourselves that it's pretty darn cold.
I'm not all that hopeful for superconducting. At what point does the energy required to reach superconducting conditions break even with the energy saved? I'd rather see a more decentralized grid where we are less dependent on electrons shipped long distances. No matter what you're moving, the farther you move it, the more it costs.

bw said...

I had the links to some places that are selling the -86C freezers.

The superconducting engines and wires made from the older YCBO type superconductors can already pay back the energy savings.

Korea and American Superconductor are making better engines, generators and wires. They pack in some liquid nitrogen or other coolant around the wires. The engines are going to be used for navy ships and commercial ships and industrial applications. Hopefully the new materials at higher temps will be developed over the next few years and have other superior features. But it took quite a while for the other superconductors.