History and Progress
- April 1986 - The term high-temperature superconductor was first used to designate the new family of cuprate-perovskite ceramic materials discovered by Johannes Georg Bednorz and Karl Alexander Müller, for which they won the Nobel Prize in Physics the following year. Their discovery of the first high-temperature superconductor, LaBaCuO, with a transition temperature of 35 K, generated great excitement.
- LSCO (La2-xSrxCuO2) discovered the same year.
- January 1987 - YBCO was discovered to have a Tc of 90 K.
- 1988 - BSCCO discovered with Tc up to 107 K, and TBCCO (T=thallium) discovered to have Tc of 125 K.
- As of 2009, the highest-temperature superconductor (at ambient pressure) is mercury barium calcium copper oxide (HgBa2Ca2Cu3Ox), at 138 K and is held by a cuprate-perovskite material, possibly 164 K under high pressure.
- Recently, other unconventional superconductors, not based on cuprate structure, have been discovered. Some have unusually high values of the critical temperature, Tc, and hence they are sometimes also called high-temperature superconductors.
After more than twenty years of intensive research the origin of high-temperature superconductivity is still not clear, but it seems that instead of electron-phonon attraction mechanisms, as in conventional superconductivity, one is dealing with genuine electronic mechanisms (e.g. by antiferromagnetic correlations), and instead of s-wave pairing, d-waves are substantial.
One goal of all this research is room-temperature superconductivity.
Read more about this topic: Unconventional Superconductor
Famous quotes containing the words history and, history and/or progress:
“All objects, all phases of culture are alive. They have voices. They speak of their history and interrelatedness. And they are all talking at once!”
—Camille Paglia (b. 1947)
“What has history to do with me? Mine is the first and only world! I want to report how I find the world. What others have told me about the world is a very small and incidental part of my experience. I have to judge the world, to measure things.”
—Ludwig Wittgenstein (1889–1951)
“Today democracy, liberty, and equality are words to fool the people. No nation can progress with such ideas. They stand in the way of action. Therefore we frankly abolish them. In the future each man will serve the interest of the state with absolute obedience. Let him who refuses beware.”
—Charlie Chaplin (1889–1977)