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There is a type of ceremic which can become a superconductor at about -197 degree celsius. What property does this material possess to make it able to become a superconductor at such a relatively high temperature (other materials are superconductors at a much lower temp.)
You've asked a great question. People have been trying to figure out
why a number of oxide compounds superconduct at rather high
temperatures for over 15 years now. There's been some progress, but not
any one answer that everybody agrees on.
One of the main theories of some high-temperature
superconductors is based on a coupling between electrons due to their
mutual coupling to short-range magnetic fluctuations. The magnetic
fluctuations play the same role that sound waves play in ordinary
I think that all the high-temperature superconductors have
sheets of fairly good conductor partially isolated by poorly conducting
sheets. This nearly two-dimensional property of the conducting sheets
seems to be important in letting them form superconducting order
without freezing into some sort of other order (e.g. magnetism) that
tends to arise in normal 3-D materials.
(republished on 07/25/06)
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