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Still, there are hints that some of the physical barriers, at least, are starting to fall. At the March meeting, scientists were already showing rings and flexible tapes made of high-temperature superconductors; by the end of the month, teams at IBM, Bell Labs, Toshiba, Argonne and a handful of other places were developing wire-thin ceramic rods. Says Toshiba's Horigami: "We weren't even sure this was possible. When we finally had a wire that could potentially be coiled, there was absolutely no way to measure our sense of triumph." Argonne Ceramist Roger Poeppel now talks of building a furnace ten feet long to fire his group's wire almost continuously as it is extruded. "We think it will be flexible enough to twist into cable," he says, "and cable is the building block for magnetic coils and electrical transmission lines. With two miles of wire, we'll make a superconducting magnet. To get a practical device + is now the race."
Later, in April, scientists at Stanford and IBM announced that they had made thin films of the new substances, important for computer applications. The spotlight then shifted to IBM Researchers Robert Laibowitz and Roger Koch, who reported that they had made their own thin film into a working gadget called a SQUID (for superconducting quantum interference device). Such tools are already used in low-temperature versions to measure extremely faint magnetic fields. They are also employed by physicists in the search for elusive gravity waves and magnetic monopoles, predicted by some theories but not yet observed. Medical researchers use SQUIDs to detect the minute fields generated by electrical activity within the brain. High-temperature SQUIDs should make all these searches a little easier.
Other scientists are seeking a better understanding of why the ceramics become superconductors. Many labs have taken pictures of the materials with electron microscopes, pulsed beams of neutrons, X rays and ultrasound. A team of Bell Labs and Arizona State scientists has produced electron-microscope photographs that show defects in the compound's crystalline structure. Says Team Leader Abbas Ourmazd: "We don't quite understand what role the defects play, but it raises some provocative questions. Is it the perfect material that is superconducting? Or is it the defects? If it turns out that it is the defects, then we will want to control them and increase their density and put them in intentionally."
Most intriguing of all are reports that the temperature record set by Chu and since matched by dozens of other researchers has already been surpassed. Some physicists have even reportedsuperconductivity-re lated effects -- though not true superconductivity -- at the torrid heights of 240 K, or -27 degrees F, which is warmer than many wintry nights in North Dakota.