Thermal Conductivity of Solids at Low Temperatures
There are three main types of solids whose thermal conductivity is important in the design of cryogenic apparatus: pure metals, alloys and disordered dielectrics. Representative conductivity curves are given in Figure 1. Several relations can be pointed out briefly: Near the conductivity maximum, around 20°K, metals have a conductivity 100 times as large as the alloys. The alloys themselves differ by a factor of ten in their conductivities at those temperatures. The disordered dielectrics like glass and plastics have very low conductivities; but in contrast, the crystal dielectrics like sapphire have a very high conductivity. It should also be noted that the temperature dependences as well as the absolute magnitudes of the conductivities of these three materials are different.
KeywordsThermal Conductivity Heat Sink Heat Leak Thermocouple Wire Lead Copper
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- 1.R. L. Powell and W. Blanpied, The Thermal Conductivity of Metals and Alloys at Low Temperatures, NBS Circular 556 (1954).Google Scholar