Supraleitende

Supraleitende is a German term referring to superconductivity. Superconductivity is a phenomenon observed in certain materials when they are cooled below a critical temperature. In this state, these materials exhibit two key properties: zero electrical resistance and the expulsion of magnetic fields.

When a material becomes superconducting, electricity can flow through it indefinitely without any loss of energy. This means that once a current is initiated in a superconducting loop, it will continue to flow forever as long as the material remains below its critical temperature. The second characteristic property of superconductivity is the Meissner effect, where the superconductor expels magnetic field lines from its interior. If a magnet is brought near a superconductor, the superconductor will generate currents on its surface that create an opposing magnetic field, effectively pushing the external field away. This effect can levitate magnets.

The critical temperature at which a material becomes superconducting varies widely. For some elements, like mercury, it is very low, around 4.2 Kelvin (-269 degrees Celsius). Other materials, known as high-temperature superconductors, have critical temperatures that are significantly higher, though still well below room temperature. These materials often contain complex ceramic oxides.

The applications of superconductivity are vast and continue to be an area of active research and development. These include powerful electromagnets used in MRI machines and particle accelerators, high-speed magnetic levitation trains (maglev), efficient power transmission lines, and advanced computing devices. The development of materials that superconduct at higher temperatures remains a major goal in physics and materials science, as it would enable a wider range of practical and energy-saving technologies.