Better Understanding of an Upcoming Superconductor
Some believe that in the future superconductors will be employed to transmit electricity over great distances and even improve the performance of our computers. While those are definitely some uses for superconductors, others include particle accelerators and MRI machines. Researchers at North Carolina State University have recently made some interesting discoveries concerning one superconductor that may be used in those applications.
Superconductors are materials that are able to conduct electricity without resistance, under certain conditions. This has obvious implications in transmitting power, but by building a superconducting ring it is possible to create very powerful magnetic fields. Such fields are used in MRI machines, for peering inside bodies, and in particle accelerators. One high temperature superconductor called bismuth strontium calcium copper oxide, or Bi2212, is of special interest as it is the only high temperature superconductor that can be made into a round wire. Producing it is tricky though, as it requires heat treating filaments to nearly 900 ºC, and at this temperature, impurities form. The North Carolina researchers investigated the impacts of these impurities, and found that they can have both a positive and negative effect on the superconductor.
Previous research showed that impurities of a large size will impair the superconductor's performance, but if they are between 1.2 and 2.5 nm wide, they will actually improve it. The reason is that at this size the impurities grab magnetic vortices and hold them in place. This prevents the vortices from disrupting the flow of the electrons, and causing resistance. With this new knowledge it may be possible to optimize the production of Bi2212 for better performance.
Source: North Carolina State University