The shocked state of superconductors.The shocked state of superconductors Blasting crystals of a high-temperature, oxide superconductor A material that has little resistance to the flow of electricity. Traditional superconductors operate at absolute zero (-459.67 degrees Fahrenheit or -273.15 degrees Celsius). Experiments in the 1980s raised the temperature to -321 degrees Fahrenheit. with a shock wave can substantially increase the material's capacity to carry electrical current, reports a research team led by William J. Nellis of the Lawrence Livermore Lawrence Livermore may refer to:
The team uses a gas-powered gun to fire lightweight, plastic projectiles at small samples of bismuth strontium calcium copper oxide Bismuth strontium calcium copper oxide, or BSCCO (pronounced "bisko"), is a family of high-temperature superconductors having the generalized chemical formula Bi2Sr2CanCun+1O2n+6. in powder form. The resulting shock wave deforms the material, apparently creating tiny defects in its crystal structure. Those defects help anchor lines of magnetic flux, which penetrate the material when it's immersed in a magnetic field. Normally, even a modest electric current can shunt To divert, switch or bypass. the flux lines aside, and the material loses its superconducting properties (SN: 2/10/90, p.95). Measurements of the magnetic characteristics of the shocked crystals confirm they can carry larger superconducting currents than unshocked samples. The researchers are also trying the technique on yttrium barium copper oxide Yttrium barium copper oxide, often abbreviated YBCO, is a chemical compound with the formula YBa2Cu3O7. This material, a famous "high-temperature superconductor", achieved prominence because it was the first material to achieve superconductivity . Shock-wave processing has several advantages over other recently investigated techniques for creating defects to pin flux lines and increase the current superconductors can carry, Nellis says. Irradiating materials with neutrons, for instance, is impractical on an industrial scale, whereas the use of shock-wave techniques based on relatively simple, conventional explosives for the large-scale processing of high-temperature superconductors seems feasible. Ivars Peterson reports from Anaheim, Calif., at an American Physical Society The American Physical Society was founded in 1899 and is the world's second largest organization of physicists. The Society publishes more than a dozen science journals, including the world renowned Physical Review and Physical Review Letters, and organizes more than twenty science meeting |
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