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French Scientists Report Superconductor Breakthrough

TIMES SCIENCE WRITER

In what some scientists are calling a potentially major breakthrough, French researchers said in a news report Wednesday that they have made a new material that carries electricity friction-free at room temperature--a long-sought discovery that could revolutionize the electric power industry.

Such so-called “superconductors” normally work only at frigid temperatures, requiring expensive refrigeration systems. The French discovery purportedly boosts the temperature by 200 degrees over other superconductors developed thus far, making the technology cheap enough to be practical. The report appeared in a Reuters story from France.

“If it’s true, it would be very, very exciting,” said physicist Paul Chu, who heads the Texas Center for Superconductivity. Chu said such a discovery could open up an entirely new direction for research into these mysterious materials that promise to deliver electricity without energy loss--the ultimate free lunch.

During the past decade, promises of practical superconductors have surfaced time and time again, only to be proved false or unworkable. “Mostly, [these claims] are wrong; they tend to go away,” said superconductivity theorist Steve Kivelson of UCLA. However, a 200-degree jump in working temperature is too tantalizing to dismiss.

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Physicist Robert Hawsey, who manages the superconductivity program at Oak Ridge National Laboratory, pointed out that nothing theorists know about superconductivity rules out the existence of a compound that superconducts at room temperature. At the same time, he admitted, their understanding is still so tenuous that it doesn’t rule out much of anything. “There’s still a lot we have to learn,” he said, “but it would be very exciting if it’s true.”

Chu, who developed the superconductor that works at the highest temperature thus far, said he had previously worked on a similar compound, a mixture of hydrogen, beryllium and lithium. “I looked into this compound in 1986. It was very difficult to make.” So he turned to other, easier-to-make compounds. “If they made it superconducting, that’s great.”

The French researchers, Jean-Pierre Bastide and Serge Contreras, are both with the National Institute of Applied Science in Lyon. They told Reuters they have submitted their findings to the Proceedings of the Academy of Sciences in Paris.

A few years ago, another French group made a similar announcement, said Hawsey, and it had to be withdrawn. “It turned out not to be true. We have to be careful. We have to take this very slowly.”

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However, it’s likely that other labs will now investigate this new compound, said Chu. “I think this is too important to ignore.”

Superconductors were discovered serendipitously in 1911, but remained mostly a laboratory curiosity because the temperatures required to sustain them hovered at just a few degrees above absolute zero--which is minus 459 degrees Fahrenheit.

In 1986, the surprising discovery of “high temperature” superconductors, which kept their ability to carry electricity without losses when hundreds of degrees warmer, caused a frenzy in the physics community and turned the spring meeting of the American Physical Society in New York into a rowdy event that became known as the “Woodstock of physics.”

However, subsequent attempts to understand these new materials came to naught, and physicists still can’t explain how they work. At the same time, the ceramic-like materials proved brittle and difficult to bend into wires, making them useless for most electrical applications.

Advances over the last few years have made possible the production of relatively short stretches of superconducting cables, but the technology is still far from widely applicable. The materials still aren’t hardy enough for many industrial purposes--for use in electric motors, for example--and require complex liquid nitrogen cooling.

The material made by the French researchers is a powder rather than a solid. But Chu said that wasn’t necessarily an obstacle, because the 1986 materials were powders at first, and only later were developed into solids. Chu was also encouraged because the latest material is similar in structure. “It’s just like the oxide structure, but with hydrogens instead of oxygens,” he said.

Neither Chu nor any of the other physicists had any information about the finding. U.C. Berkeley’s Marvin Cohen, a top theorist in the field, said he had recently returned from a scientific meeting in France and had heard nothing of the discovery.


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