CERAMIC MATERIAL AND THERMAL SWITCH

摘要

Provided are a ceramic material, the thermal conduction performance of which can be changed depending on temperature, and a thermal switch using the same. In the ceramic material, when the mean free path length of phonons as appearing at room temperature is defined as LAMFP=(3×thermal conductivity)∕(thermal capacity×speed of sound), the characteristic length (La) of a microstructure is 0.1 LAMFP≤La≤100LAMFP, and the thermal conductivity monotonically increases between room temperature and 100ºC. The characteristic length (La) of the microstructure is: the spacing between grains of different materials in the event of a composite material in which different materials are dispersed in a base material; the spacing between an air hole and an air hole in the event of a porous body; or the crystal grain size (the spacing between a grain boundary and a grain boundary) in the event of a polycrystalline body.