Superconducting Ceramics Trigger Futuristic Dreams : Competition From Japan Will Be One Topic at Meeting This Week
Theoretical physicists, who have long toiled in obscurity, have suddenly developed an unaccustomed celebrity.
“I feel like a teen-age girl who has never been attractive and then changes overnight,” said Marvin Cohen of UC-Berkeley. But, he added, “we’re very happy and we’re having fun.”
What has elated Cohen--and thousands of other researchers--is the recent discovery of a new family of materials capable of conducting electricity without any losses due to resistance at much higher temperatures than existing materials. That discovery has been hailed as the most important development in physics since the development of the transistor.
Physicists have long known that when many materials such as mercury and lead are cooled to temperatures near 0 degrees Kelvin (minus 460 degrees Fahrenheit), they lose all resistance to electricity, becoming superconductors. But the costs of cooling such superconductors to those low temperatures are so high that the materials have few practical uses.
Progress Comes Suddenly
For 75 years, until less than a year ago, researchers periodically found new materials that pushed superconducting temperatures up a degree or two at a time. But then suddenly, since November, physicists have discovered a new family of ceramic materials that raise superconducting temperatures more than 60 degrees Kelvin, to a point at which cooling can be achieved with liquid nitrogen, which is much more efficient and much less costly than the liquid helium required previously.
The advent of these new superconducting materials has triggered many futuristic predictions of how they will improve life. Some visionaries see, for instance, smooth-riding trains that levitate above their rails on powerful magnetic fields, more efficient generation and transmission of electricity and new computers that are both faster and smaller than today’s mainframes.
And if still higher temperatures can be achieved, which many experts think is likely, the materials might lead to powerful motors only a tenth as large as today’s and lightweight, efficient electrical cars that would draw their energy from on-board superconducting storage rings rather than from burning gasoline.
But many obstacles loom. The new superconductors are brittle, and their current-carrying capacity is much lower than that of existing superconductors.
The promise of superconductivity will be the topic of a high-profile conference in Washington on Tuesday and Wednesday sponsored by the White House Office of Science and Technology Policy and the Department of Energy. Nearly 1,000 businessmen and scientists are expected to attend.
Reagan Keynote Speaker
The keynote speaker is to be President Reagan, who also met last week with his Economic Policy Council to consider the federal role in the development of superconductivity.
“This conference will focus on ways we can transform our pre-eminence in basic research into innovative and marketable applications,” said Secretary of Energy John S. Herrington. “We’ve invited people from electric companies, transportation companies, computer companies--everyone we thought might be able to use superconductors,” added a Department of Energy spokesman.
One topic of discussion clearly will be the Japanese response to the discovery of new superconducting materials. Even as U.S. researchers were leapfrogging one another with rapid announcements of increasingly higher-temperature materials, Japan’s vaunted Ministry of International Trade and Industry had already launched a program to expedite the development of products from the new superconductors. MITI’s actions have caused concern in the United States that Japan will capture a large segment of the superconductivity market, repeating its successes with electronics and automobiles.
“How we get our superconductivity science to the market, how we compete in the race with the Japanese and others, will have enormous implications for future world leadership,” said Rep. Don Ritter (R-Pa.), who is to chair a workshop on “Industry/Government/University Cooperation” at the conference.
Ritter is also one of the sponsors of a bill that would create a national commission on superconductors to examine ways to accelerate their use in commercial and defense applications. The bill was approved Thursday by the House Science, Space and Technology Committee and made part of a package of measures on international competitiveness. The bill is scheduled for consideration by a House-Senate conference committee after Labor Day.
Discovered in 1911
Superconductivity was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes. But by 1986, the highest temperature at which superconductivity was observed had been pushed up only to 23.2 degrees Kelvin (minus 419 degrees Fahrenheit), for an alloy of niobium and germanium discovered in 1973. But research waned because of the perception that physicists had reached a seemingly impassable barrier.
But physicist K. Alex Muller of the IBM Zurich Research Laboratory in Switzerland reasoned that certain electronic properties of metal oxides might enable them to become superconductors, even though most metal oxides are insulators.
After three years of synthesizing hundreds of ceramics, he and his colleague J. Georg Bednorz last year reported the discovery of one that became superconducting at 35 degrees Kelvin--a remarkable 12 degrees above the previous record.
Jump to 94 Degrees K.
Following up on the Swiss results, chemist Paul C. W. Chu of the University of Houston announced Feb. 13 that he had made a ceramic that became superconducting at 94 degrees Kelvin (minus 291 degrees Fahrenheit), above the boiling point of liquid nitrogen, making cooling much cheaper.
Since then, scientists have found at least 13 similar ceramics with superconducting temperatures in the 90-degree Kelvin range. Some have also seen fleeting evidence of superconductivity at temperatures as high as 298 degrees Kelvin (78 degrees Fahrenheit), but these findings have not proved confirmed.
Meanwhile, theorists are trying to understand why the ceramics are superconducting--so far without much success, Cohen said.
Obstacles Remain
But discovering the superconductors is only the first step in a long process of development. Because these materials are ceramics, they are brittle and easily breakable. They also can carry only limited amounts of electrical current, about the same amount carried by the wiring of a house. And if large currents cannot be carried, the powerful magnetic fields required to levitate trains, for example, cannot be produced.
Scientists at AT&T; Bell Laboratories in Murray Hill, N.J., in April manufactured wires of the new material that are flexible enough to be wound into electromagnets. And researchers at IBM Corp. in Yorktown Heights, N.Y., showed in May that individual crystals of the materials can carry very large currents--indicating that a low current-carrying capacity is not an inherent problem of the materials.
‘A Long Way to Go’
But the Bell wire could not carry much current, and the single crystals cannot be grown much longer than an inch, much too short for a wire. “We clearly have a long way to go,” said chemist Donald Capone of Argonne National Laboratory in Illinois.
Capone and others noted that the superconductors now in use faced similar problems during their development. These problems were eventually overcome, making researchers confident now that the new problems also can be solved.
Some experts, such as Mario Rabinowitz of the Electric Power Research Institute in Palo Alto, believe that the first application of the new materials could be for long-distance transmission of electricity.
Energy Loss Costly
For power transmission, about 1% of the energy is lost due to resistance for each 100 miles of cable. That loss costs U.S. power companies $10 billion annually, Rabinowitz said. Pacific Gas & Electric and Southern California Edison officials say their energy losses run between 5% and 8% annually, with PG&E;’s totaling $200 million a year.
Superconducting transmission lines could reduce such losses but are expensive because they must be underground for thermal insulation, according to physicist Eric B. Forsythe of Brookhaven National Laboratory in New York. Superconducting lines would thus most likely be used only where lines must be underground anyway, such as on the densely populated East Coast, he said.
A more likely use in California might be a superconducting energy storage ring, said physicist Theodore Geballe of Stanford University. Electricity produced during low-demand periods would be injected into the ring, where it would be stored, without loss, until needed.
Testing in Tacoma
An experimental storage ring incorporating helium-cooled superconductors is already being tested by the Bonneville Power Administration in Tacoma, Wash. It stores as much as five megawatts of electricity during the night and releases it the next day during peak hours.
Smaller versions of such storage rings might also be used to power electric buses and trucks in urban areas, Geballe said.
Transportation projects such as the proposed high-speed rail link between Ontario and Las Vegas could also benefit from the new superconductors. Proponents of that link hope to use a 250-m.p.h. magnetically levitated train, and one of the prototypes being considered uses superconducting magnets.
Use in Computers
The superconductors should also find many applications in electronics, particularly in computers. Because electrical signals can travel only 15 centimeters in a billionth of a second, supercomputers must be very compact. But the semiconductor circuits produce enough heat to melt the computer if they are packed too closely, according to Juri Matisoo of IBM.
Because superconducting wires and components give off little or no heat, Matisoo said, they could be packed together as tightly as fabrication methods would allow.
The Department of Defense also may have many uses for superconductors, according to James A. Ionson of the Strategic Defense Initiative Organization. They could be critical components of satellite-based infrared detectors for identifying hostile missile launches or sensitive magnetometers for detecting submarines. Powerful superconducting magnets could also be used in “rail guns” or particle accelerators that could destroy missiles. The new materials would make the superconducting components of each of these applications cheaper and more reliable.
U.S. Develops, Japan Produces
Despite the fact that most scientific advances with the new superconductors have occurred in the United States, many researchers fear that Japan will be the first to market products made from them. “Whenever individual efforts count, we have been leaders,” said Bell physicist Bertram Batlogg. “Yet when it comes time to turn ideas into products, we are lost.”
Ritter noted the speed with which Japan reacted to the discovery of the superconductors. Within eight days after Chu’s February announcement of a 94-degree Kelvin superconductor, Japan’s MITI began assembling a consortium of university, industry and government researchers to exploit the new materials.
But a similar effort is not occurring in the United States, said Alan Schriesheim, director of Argonne National Laboratory.
Research Funding Lags
Funding is a critical problem, most experts agree. “We’ve got to pay close attention to research funding to universities. . . ,” said Bell physicist Paul Fleury. “Otherwise, the Japanese could well come out ahead of us.”
So far, the National Science Foundation has set aside only an extra $1.6 million for research on the superconductors, and the Department of Energy has increased funding from $3 million to $10 million. The Department of Defense is spending about $25 million.
MIT ceramics expert H. Kent Bowen thinks at least $100 million should be spent on the new materials, with most of it directed toward small companies and universities. If this isn’t done, he said, “where are they going to get the technology and the materials so that they can incorporate it into their products?”
Not everyone agrees that central coordination is necessary in the United States. “The discoveries have been so spectacular that the level of activity is enormous in every laboratory in the U.S. with any capability in superconductivity,” said Roland W. Schmitt, General Electric Co.’s chief scientist and president of the National Science Board.
Nonetheless, concluded Bell’s Paul Fleury, “we have to realize we are in a horse race, and business as usual will not suffice.”
