Type II Superconductors
Most recent answer: 10/22/2007
Q:
I’ve noticed that many superconductors, type two at least, involve oxygen which doesn’t allow them to be very malleable. (they become ceramics)What is the importance of oxygen in superconductors, and how do scientists determine which combination of elements will result in it?
- Kelly (age 16)
St. Louis
- Kelly (age 16)
St. Louis
A:
I think you may be mixing two ideas. There are many type II superconductors (ones which allow magnetic flux vortices to penetrate) which are ordinary metals, especially alloys, without oxygen.
Oxygen is present in the high-temperature superconducting materials, which form brittle crystals, which can be fused into ceramics. The main reasons for the high transition temperatures of these materials are not yet fully understood. One factor that plays a role is that the conduction electrons are partially confined to two-dimensional sheets. That allows them to couple rather strongly to magnetic and other fluctuations which promote superconductivity without falling into some other ordered states, like antiferromagnetism, that form more easily in three dimensions. Crystals which are close to being insulators (and oxides are the most familiar examples) are good candidates for such materials. However, there is no guarantee that all high-temperature superconductors will be oxides.
Mike W.
Oxygen is present in the high-temperature superconducting materials, which form brittle crystals, which can be fused into ceramics. The main reasons for the high transition temperatures of these materials are not yet fully understood. One factor that plays a role is that the conduction electrons are partially confined to two-dimensional sheets. That allows them to couple rather strongly to magnetic and other fluctuations which promote superconductivity without falling into some other ordered states, like antiferromagnetism, that form more easily in three dimensions. Crystals which are close to being insulators (and oxides are the most familiar examples) are good candidates for such materials. However, there is no guarantee that all high-temperature superconductors will be oxides.
Mike W.
(published on 10/22/2007)