THERMAL-CONDUCTIVITY OF DENSIFIED ALPHA-SIO2 FROM 15-5 TO ROOM-TEMPERATURE

The thermal conductivity of densified a-SiO2 has been measured from 15 K to room temperature. The sample was prepared under a uniaxial press ure of 16 GPa at room temperature. The density of the sample is about 20% higher than that of undensified a-SiO2. The thermal conductivity d isplays a plateau at temperatures up to 60 K, and the magnitude of the plateau is higher than that of undensified a-SiO2. Above 60 K, the th ermal conductivity increases approximately linearly with temperature. A simple analysis of the thermal conductivity data measured on two dif ferent portions of the sample reveal that the thermal conductivity pla teau is most strongly affected by the densification.