The thermal conductivity of densified a-${\mathrm{SiO}}_2$ has been measured from 15 K to room temperature. The sample was prepared under a uniaxial pressure of 16 GPa at room temperature. The density of the sample is about 20% higher than that of undensified a-${\mathrm{SiO}}_2$. The thermal conductivity displays a plateau at temperatures up to 60 K, and the magnitude of the plateau is higher than that of undensified a-${\mathrm{SiO}}_2$. Above 60 K, the thermal conductivity increases approximately linearly with temperature. A simple analysis of the thermal conductivity data measured on two different portions of the sample reveal that the thermal conductivity plateau is most strongly affected by the densification.

• Received 31 March 1994

DOI:https://doi.org/10.1103/PhysRevB.50.6053