The thermal conductivity of liquid He 3 at a pressure of § atmosphere has been determined experimentally and found to increase slowly from 7X10~5 watt/cm°K at 0.24°K to 16X10" 5 watt/cm°K at 2.7°K with no evidence of superfluidity. Several models of liquid He 3 based on Fermi-Dirac statistics predict a 1/T dependence for the thermal conductivity of He 3 at the lowest temperatures, but no such behavior has been observed down to 0.24°K in the present work. A study of the convective heat transport in the liquid has indicated that the coefficient of thermal expansion becomes negative below about 0.5 °K. A thermal boundary resistance across a copper-liquid He 3 interface has been found which is similar in magnitude and temperature dependence to that found for a copper-superfluid He 4 boundary.

No abstract