Kapitzaresistans

Kapitzaresistans, also known as Kapitza resistors, are a type of electrical resistor that exhibit a unique property: their resistance decreases as the temperature increases. This behavior is the opposite of what is typically observed in most materials, where resistance generally increases with temperature. This phenomenon is due to the Kapitza resistance, which is the thermal resistance at the interface between two materials.

Kapitzaresistans are typically composed of two layers of different materials. The interface between these layers is where the Kapitza resistance occurs. This resistance is caused by the scattering of phonons, which are quanta of lattice vibration, at the interface. As the temperature increases, the number of phonons also increases, leading to more scattering and thus a decrease in resistance.

These resistors have potential applications in various fields, including thermoelectrics and thermal management. They can be used to create temperature-dependent circuits and sensors. However, their use is limited by the fact that they are typically only effective over a narrow temperature range.

Kapitzaresistans were first observed in the 1930s by Pyotr Kapitza, a Russian physicist. Since then, they have been the subject of extensive research, with many different materials and structures being explored to optimize their performance. Despite this, they remain a relatively niche area of study in the field of materials science and electrical engineering.