Science: Superconductors!

The startling breakthrough that could change our world

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Muller and his colleague, Johannes Georg Bednorz, tinkered with hundreds of different oxide compounds over the next few years, varying quantities and ingredients like alchemists in search of the philosopher's stone. Finally, in December 1985, they came across a compound of barium, lanthanum, copper and oxygen that seemed promising. When Bednorz tested the compound, he was startled to see signs of super-conductivity at an unprecedented 35 K, by far the highest temperature at which anyone had observed the phenomenon. Could this result be correct? Aware of some hastily made superconductivity claims that later could not be reproduced, the IBM team proceeded cautiously, painstakingly repeating their experiments. In April 1986, Muller and Bednorz finally submitted the findings to the German journal Zeitschrift fur Physik, which published it five months later.

As Muller had anticipated, other physicists were skeptical. For one thing, the IBM scientists had lacked the sensitive equipment to test for the Meissner effect, the surest proof of superconductivity, and thus could not confirm it in their report. More important, in a field where improvements of a few degrees were reason for celebration, this great a temperature leap seemed unlikely. Douglas Finnemore, a physicist at Iowa State University, admits that he was among the doubters. "Our group read the paper," he says. "We held a meeting and decided there was nothing to it."

Not everyone was so quick to dismiss the discovery. Scientists from the University of Tokyo took a look at the substance. Says Muller: "The Japanese weren't smiling, and they confirmed it. Then the United States sat up." By the end of the year, confirmation had come from China and the U.S., and suddenly a nearly moribund branch of physics was the hottest thing around. Large industrial and government laboratories jumped in; so did major universities. At Bell Labs, a team led by Bertram Batlogg and Ceramist Cava had launched their own program of alchemical tinkering. Soon they had manufactured a similar compound that became a superconductor at 38 K, one- upping their archrivals at IBM. "That's when the hysteria started," says Cava. "The place was abuzz with excitement."

But Bell Labs too was soon to be upstaged. For among those who had given early credence to the news from Zurich was a small, modestly equipped team of researchers headed by Paul C.W. Chu of the University of Houston. Chu had been studying superconductivity since 1965; now he and his group, including scientists from the University of Alabama, quickly reproduced the IBM results and moved on to their own experiments.

Since the Houston lab had special equipment for testing materials at high pressure, Chu wondered what would happen if he pressurized the IBM compound. "Using known theories," he says, "you don't expect the transition temperature to go up rapidly under pressure, but it shot up like a rocket. It suggested to us that there might be some new mechanism involved." That unexpected result, says Chu, played right into what he considers his group's strong suit: "We feel we have an advantage over some other groups because we are not confined to conventional thinking. We think wildly." Chu found that the compound remained a superconductor up to 52 K (-366 degrees F) when subjected to from 10,000 to 12,000 times normal atmospheric pressure.

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