Soret coefficients of alkali oxides in alkali borate glass melts

抄録

We measured the Soret coefficients of alkali oxides in binary alkali borate glass melts. The alkali borate glasses, 15(mol %)Li₂O–85B₂O₃, 15Na₂O–85B₂O₃, and 15K₂O–85B₂O₃, were encapsulated in platinum capsules and heat-treated at 1000°C with a temperature gradient in a tube furnace. After the heat treatment, the compositional distribution of the glass sample was measured by Raman spectroscopy. The Soret coefficients of the alkali oxides Li₂O, Na₂O, and K₂O increased with the atomic numbers of the alkali metal ions. This indicates that alkali oxides more easily have high concentration in cold regions as the atomic numbers of the alkali metal ions in the alkali oxides increase. This result provides new information about the diffusion properties in glass melts.