Superjohteista

Superjohteista is a Finnish term that translates to "superconductors" in English. Superconductors are materials that exhibit superconductivity, a phenomenon characterized by zero electrical resistance and the expulsion of magnetic fields when cooled below a certain critical temperature. This means that electric current can flow through them indefinitely without any energy loss due to heat.

The discovery of superconductivity dates back to 1911, when Dutch physicist Heike Kamerlingh Onnes observed it in mercury. Since then, numerous other materials have been found to be superconducting, including various metals, alloys, and ceramic compounds. Superconductors are broadly categorized into two types: Type I and Type II. Type I superconductors exhibit a complete expulsion of magnetic fields below their critical temperature and critical magnetic field. Type II superconductors, on the other hand, allow partial penetration of magnetic fields in a quantized form above a lower critical field but remain superconducting up to a higher critical field.

The practical applications of superconductors are vast and continuously expanding. They are crucial in the development of powerful electromagnets used in medical imaging devices like MRI scanners, in particle accelerators for scientific research, and in high-speed magnetic levitation (maglev) trains. Their ability to conduct electricity without loss also makes them promising for efficient power transmission and for building advanced electronic components. Research into higher-temperature superconductors continues, aiming to expand their use to more everyday applications by reducing the need for extremely low operating temperatures.