Room temperature superconductor; Improved fuel cell membrane
Date: Friday, March 21, 2008 @ 22:30:33 GMT
Topic: Science


Silicon compound aims to superconduct at room temperature
R. Colin Johnson/ EE Times/ (03/17/2008 5:35 PM EDT)

PORTLAND, Ore. — A new superconducting material fabricated by a Canadian-German team has been fabricated out of a silicon-hydrogen compound. Instead of super-cooling the material, as is necessary for conventional superconductors, the new material is instead super-compressed. The researchers claim that the new material could sidestep the cooling requirement, thereby enabling superconducting wires that work at room temperature.


"Our research in this area is aimed at improving the critical temperature for superconductivity so that new superconductors can be operated at higher temperatures, perhaps without a refrigerant," said Tse.

He performed the theoretical work with doctoral candidate Yansun Yao. The experimental confirmation was performed by researcher Mikhail Eremets at the Max Planck Institute in Germany.

The new family of superconductors are based on a hydrogen compound called "silane," which is the silicon analog of methane--combining a single silicon atom with four hydrogen atoms to form a molecular hydride. (Methane is a single carbon atom with four hydrogens).

Researchers have speculated for years that hydrogen under enough pressure would superconduct at room temperature, but have been unable to achieve the necessary conditions (hydrogen is the most difficult element to compress). The Canadian and German researchers attributed their success to adding hydrogen to a compound with silicon that reduced the amount of compression needed to achieve superconductivity.

Tse's team is currently using the Canadian Light Source synchrotron to characterize the high pressure structures of silane and other hydrides as potential superconducting materials for industrial applications as well as a storage mechanism for hydrogen fuel cells.

The research was funded by the National Sciences and Engineering Research Council of Canada, the Canada Research Chairs program, the Canada Foundation for Innovation and the Max Planck Institute.

(Editor's Note: This is a slightly corrected version of the original story, which intimated that the silicon compound was tested at room temperature. It was not. However, nor was it "supercooled," so it is expected to lead to room-temperature superconductivity in the future.)

Source: Silicon compound superconduct
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Findings Could Improve Fuel Cell Efficiency

Researchers at Duke’s Pratt School of Engineering have developed a membrane that allows fuel cells to operate at low humidity and theoretically at higher temperatures.


A new type of membrane based on tiny iron particles appears to address one of the major limitations exhibited by current power-generating fuel cell technology.

While there are many types of fuel cells, in general they generate electricity as the result of chemical reactions between an external fuel -- most commonly hydrogen -- and an agent that reacts with it. The membrane that separates the two parts of the cell and facilitates the reaction is a key factor in determining the efficiency of the cell.

Fuel cells are commonly used in such settings as satellites, submarines or remote weather stations because they have no moving parts, do not require combustion and can run unattended for long periods of time. However, current fuel cells lose efficiency as the temperature rises and the humidity falls.

Researchers at Duke University’s Pratt School of Engineering have developed a membrane that allows fuel cells to operate at low humidity and theoretically to operate at higher temperatures. They reported their findings online in the Journal of Membrane Science. ...

Full story: http://www.physorg.com/news125157863.html







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