Neutron Scattering Study of the Low-Frequency Vibrations in Vitreous Silica

作者：Ulrich Buchenau, N. Nücker, A.J. Dianoux · 发表于：Physical Review Letters · 年份：1984 · DOI：10.1103/physrevlett.53.2316 · 被引用次数：425 · 研究领域：Glass properties and applications、Mineralogy and Gemology Studies、Geological and Geochemical Analysis

The vibrational excitations in vitreous silica above 150 GHz were investigated at 50, 100, and 290 K by inelastic scattering of cold neutrons. A detailed study of the frequency and wave-vector dependence shows that even at the lowest frequencies only a small part of the scattering is due to acoustic phonons. The type of motion of the dominating additional low-frequency modes is identified as a coupled rotation of Si${\mathrm{O}}_{4}$ tetrahedra. Possible connections to the low-temperature glass anomalies are discussed.