Developments in Brief : Superconductivity Temperatures Raised
Two research groups have increased the temperature at which superconductivity will occur--a discovery with broad implications for energy storage and electrical generation and transmission.
Superconductivity is a phenomenon in which electricity can pass through conductors without resistance. It was originally thought to occur only at temperatures close to absolute zero, or minus 459.7 degrees Fahrenheit, the temperature at which the normal motion of molecules ceases.
Although scientists in 1973 raised the temperature at which superconductivity occurs to minus 417.6 degrees Fahrenheit, it was not until two years ago that others were able to raise it again, by one degree.
Last week, Paul C. W. Chu, a physics professor at the University of Houston, said he and his assistants raised the temperature to minus 387 degrees. At the same time, researchers at AT&T; Bell Laboratories in Murray Hill, N.J., achieved minus 390.1 degrees, said Bob Dynes, director of chemical and physics research.
Chu said advances in superconductivity could eventually be used in many areas, including generating, storing and transmitting electricity, because almost no power would be lost in transmission through a superconducting power line.
If such a transmission process could be perfected, Dynes said, power plants could be built away from those they serve and not lose energy during transmission.
The research work done by Chu and Bell Laboratories is scheduled to be published this month in Physical Review Letters, a physics journal.
The University of Houston scientists used liquid helium to cool the conductors. Ultimately, scientists hope to use liquid nitrogen, which is cheaper and better at cooling, said Roy Weinstein, dean of natural science at the University of Houston. Liquid nitrogen has a temperature of minus 320.8 degrees.
Chu said he used a lanthanum-barium-copper-oxide conducting material and subjected it to pressure of a few hundred thousand pounds per square inch.
