Thomsoneffekten

Thomsoneffekten, also known as the Thomson effect or Kelvin effect, is a thermoelectric phenomenon observed in a conductor when an electric current flows through it. Unlike the Seebeck effect, which generates a voltage due to a temperature difference, or the Peltier effect, which causes heating or cooling at a junction of two different materials, the Thomson effect occurs within a single, homogeneous conductor. When a current passes through a material that has a temperature gradient, heat is either absorbed or released.

The direction and magnitude of this heat absorption or release depend on the sign of the Thomson coefficient of the material and the direction of the current relative to the temperature gradient. If the current flows from a hotter region to a colder region in a material with a positive Thomson coefficient, heat is absorbed by the conductor. Conversely, if the current flows from a colder region to a hotter region, heat is released. For materials with a negative Thomson coefficient, the effect is reversed. This phenomenon is a consequence of the interaction between the charge carriers (electrons or holes) and the lattice vibrations of the conductor.

The Thomson effect is generally much weaker than the Peltier and Seebeck effects. It plays a role in the overall energy balance of thermoelectric devices and in understanding heat transfer in conductors under current flow. While not as widely utilized for practical applications as the other thermoelectric effects, its study contributes to a more complete understanding of the thermoelectrical properties of materials.