The thermal expansion of vitreous silica is negative at low temperatures. This negative expansion can be explained as being caused by the transverse vibrations of the oxygen atoms. The frequency of such vibrations, because of the structure of vitreous silica, decreases as the structure shrinks, and this decrease results in negative thermal expansion.
No takes yet. Share an insight, caveat, or question.
Harold T. Smyth (1955) studied this question.
Synapse has enriched one closely related paper. Consider it for comparative context: