A hydocarbon superconductor

[docm]

http://spectrum.ieee.org/energy/the-sma ... discovered

Hydrocarbon Superconductor Discovered

Picene becomes a superconductor below 18 kelvin

3 March 2010—In a development that if independently confirmed could lead to an entirely new class of superconductors, a group of Japanese scientists—led by Professor Yoshihiro Kubozono of Okayama University—is reporting that a simple hydrocarbon, picene, exhibits superconductivity below 18 kelvin, a relatively high temperature. The Japanese team details its findings in this week’s issue of Nature .

Superconductivity is a phenomenon whereby the resistance of a material to the flow of electricity vanishes. If confirmed, this will be the first time in a decade that a new organic, high-temperature superconductor has been discovered.

”The results look quite interesting, and I would expect [them] to cause a stir in the superconductivity community,” says Jeff Lynn, a physicist at the National Institute of Standards and Technology (NIST), in Gaithersburg, Md., who investigates superconductivity.

Kubozono and colleagues have found that picene becomes a superconductor when it is laced with potassium or rubidium and then chilled. Picene is an organic compound found in crude oil; it is made up of 22 carbon atoms and 14 hydrogen atoms. It looks like five benzene rings—common organic molecules—fused together in a staggered line.

”Most people…wouldn’t think of hydrocarbons as being electrically interesting,” says the University of Liverpool’s Matthew Rosseinsky and Durham University’s Kosmas Prassides, who coauthored a commentary in Nature explaining the significance of the work. ”This is exciting news for superconductivity researchers and should stimulate extensive work on the electronic properties of other acenes [the family of aromatic compounds to which picene belongs].”

The Japanese team doped the molecules with potassium or rubidium in a process called intercalation, in which the metal atoms are inserted between parts of the picene molecule. They created a thin film of the intercalated picene and built a field-effect transistor to test for superconductivity.
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[emperor_of_localgroup]

http://spectrum.ieee.org/energy/the-smarter-grid/hydrocarbon-superconductor-discovered

Hydrocarbon Superconductor Discovered

Picene becomes a superconductor below 18 kelvin

3 March 2010—In a development that if independently confirmed could lead to an entirely new class of superconductors, a group of Japanese scientists—led by Professor Yoshihiro Kubozono of Okayama University—is reporting that a simple hydrocarbon, picene, exhibits superconductivity below 18 kelvin, a relatively high temperature. The Japanese team details its findings in this week’s issue of Nature .

>

If my memory is not failing, didn't physicists already make superconductors at much higher temperatures?
Not quite at room temperature, but well above 18[super]o[/super]K, IIRC.

 

[Ishimura_]

I think this is special because it's an organic superconductor

 

[GraemeH]

I think this is special because it's an organic superconductor

Yup, what makes it special is that it is a hydrocarbon organic superconducter as opposed to a standard carbon organic superconductor - the latter being inorganic doped carbon only material (for example, fullerene - commonly referred to as buckyballs and carbon nanotubes).

 

[a_lost_packet_]

A somewhat related article in as much as generating something unexpected relating to nanomaterials..

MIT researchers discover new way of producing electricity[/url]":3jt3s3px]

(PhysOrg.com) -- A team of scientists at MIT have discovered a previously unknown phenomenon that can cause powerful waves of energy to shoot through minuscule wires known as carbon nanotubes. The discovery could lead to a new way of producing electricity, the researchers say.

The phenomenon, described as thermopower waves, “opens up a new area of energy research, which is rare,” says Michael Strano, MIT’s Charles and Hilda Roddey Associate Professor of Chemical Engineering, who was the senior author of a paper describing the new findings that appeared in Nature Materials on March 7. The lead author was Wonjoon Choi, a doctoral student in mechanical engineering.

Like a collection of flotsam propelled along the surface by waves traveling across the ocean, it turns out that a thermal wave — a moving pulse of heat — traveling along a microscopic wire can drive electrons along, creating an electrical current. ...

A previously unknown phenomenon

In the new experiments, each of these electrically and thermally conductive nanotubes was coated with a layer of a reactive fuel that can produce heat by decomposing. This fuel was then ignited at one end of the nanotube using either a laser beam or a high-voltage spark, and the result was a fast-moving thermal wave traveling along the length of the carbon nanotube like a flame speeding along the length of a lit fuse. Heat from the fuel goes into the nanotube, where it travels thousands of times faster than in the fuel itself. As the heat feeds back to the fuel coating, a thermal wave is created that is guided along the nanotube. With a temperature of 3,000 Kelvin, this ring of heat speeds along the tube 10,000 times faster than the normal spread of this chemical reaction. The heating produced by that combustion, it turns out, also pushes electrons along the tube, creating a substantial electrical current.

Combustion waves — like this pulse of heat hurtling along a wire — “have been studied mathematically for more than 100 years,” Strano says, but he was the first to predict that such waves could be guided by a nanotube or nanowire and that this wave of heat could push an electrical current along that wire....

(Emphasis mine)

 

[silylene]

Apparently the trick is that a staggered line of fused aromatic rings is required, because the metal dopant atom lies in the cavities.

The higher analogues, C26H16 and C30H18 would be interesting to study.

I bet picene is a potently strong carcinogen precursor. Mutagenicity and carcinogenicity of the fused aromatic molecules is very well predicted by the presence of "bays", formed by the staggered topology of the fused rings. When bays are present, the terminal aromatic ring is easily oxidized to an epoxide diol. For example, benzo(a)pyrene, which has 1 bay, is the precursor to the most potent carcinogen which is found in cigarette and coal tars. I did a very nice paper on the mechanism of this toxicity mechanism many years ago!

 

[GraemeH]

A somewhat related article in as much as generating something unexpected relating to nanomaterials..

MIT researchers discover new way of producing electricity[/url]":1xzuit4m]

(PhysOrg.com) -- A team of scientists at MIT have discovered a previously unknown phenomenon that can cause powerful waves of energy to shoot through minuscule wires known as carbon nanotubes. The discovery could lead to a new way of producing electricity, the researchers say.

The phenomenon, described as thermopower waves, “opens up a new area of energy research, which is rare,” says Michael Strano, MIT’s Charles and Hilda Roddey Associate Professor of Chemical Engineering, who was the senior author of a paper describing the new findings that appeared in Nature Materials on March 7. The lead author was Wonjoon Choi, a doctoral student in mechanical engineering.

Like a collection of flotsam propelled along the surface by waves traveling across the ocean, it turns out that a thermal wave — a moving pulse of heat — traveling along a microscopic wire can drive electrons along, creating an electrical current. ...

A previously unknown phenomenon

In the new experiments, each of these electrically and thermally conductive nanotubes was coated with a layer of a reactive fuel that can produce heat by decomposing. This fuel was then ignited at one end of the nanotube using either a laser beam or a high-voltage spark, and the result was a fast-moving thermal wave traveling along the length of the carbon nanotube like a flame speeding along the length of a lit fuse. Heat from the fuel goes into the nanotube, where it travels thousands of times faster than in the fuel itself. As the heat feeds back to the fuel coating, a thermal wave is created that is guided along the nanotube. With a temperature of 3,000 Kelvin, this ring of heat speeds along the tube 10,000 times faster than the normal spread of this chemical reaction. The heating produced by that combustion, it turns out, also pushes electrons along the tube, creating a substantial electrical current.

Combustion waves — like this pulse of heat hurtling along a wire — “have been studied mathematically for more than 100 years,” Strano says, but he was the first to predict that such waves could be guided by a nanotube or nanowire and that this wave of heat could push an electrical current along that wire....

(Emphasis mine)

Hi a_l_p,

Yes, very interesting! Just for information, the BBC report on the above discloses that the fuel was cyclotrimethylenetrinitramine ( http://news.bbc.co.uk/1/hi/sci/tech/8556656.stm ) which is better known as the explosive, RDX.