Thermal Conductivity of Borate Glasses in a Range of Low Temperature

Abstract

Thermal conduction is one of the fundamental thermodynamic properties of materials. However, that of oxide glasses at low temperature has not been studied enough. In this study, thermal conductivity of Na₂O-B₂O₃ glasses in the range of temperature from about 150K to room temperature was measured by means of a transient heating method. As a result, the increase of the alkali content in this glass system is found to increase the thermal conductivity and the thermal diffusivity, together with the decrease in phonon mean free path.