The thermal conductivity of carbon - carbon fibre composites below 80 K

The thermal conductivities of some 2 dimensional carbon fibre in carbon (CCF) composite materials were measured between 1.5 K and 80 K. Measurements upon one sample were made down to 0.15 K. An analysis of the results is made and a simple model of the system was used to predict the conductivities to within ～10%.The material is a very good thermal insulator (K < 0.01 Wm^?1K^?1 at 4.2 K) with very low thermal expansion and is easy to machine. As such it may be useful as a low temperature constructional material, though the readiness with which the material adsorbs gas may limit its applications.