Superkonduktion

Superkonduktion, also known as superconductivity, is a phenomenon observed in certain materials at very low temperatures. In this state, these materials exhibit two primary characteristics: zero electrical resistance and the expulsion of magnetic fields.

When a material becomes superconducting, its electrical resistance vanishes completely. This means that an electric current can flow through it indefinitely without any energy loss due to heat. This property holds immense potential for energy transmission and advanced electronic devices.

The second key characteristic is the Meissner effect, where a superconductor expels magnetic fields from its interior. If a magnetic field is applied to a material below its critical temperature, the material will generate currents on its surface to counteract and expel the external magnetic field, causing the magnet to levitate above the superconductor.

The transition to the superconducting state occurs when the material is cooled below a critical temperature, which varies depending on the specific material. The critical temperature for most conventional superconductors is extremely low, often requiring liquid helium for cooling. However, a class of materials known as high-temperature superconductors, discovered in the 1980s, exhibit superconductivity at relatively higher temperatures, though still requiring significant cooling, typically with liquid nitrogen.

The discovery of superconductivity dates back to 1911 by Heike Kamerlingh Onnes. Since then, research has focused on understanding the underlying mechanisms and discovering new superconducting materials with higher critical temperatures and improved properties, paving the way for applications in areas like magnetic levitation trains, powerful electromagnets for MRI machines, and advanced computing.