Low-frequency modes in vitreous silica

作者：Ulrich Buchenau, M. Prager, N. Nücker, A.J. Dianoux, Naveed Ahmad, W. A. Phillips · 发表于：Physical review. B, Condensed matter · 年份：1986 · DOI：10.1103/physrevb.34.5665 · 被引用次数：559 · 研究领域：Glass properties and applications、Transition Metal Oxide Nanomaterials、Photorefractive and Nonlinear Optics

Measurements of the elastic and inelastic neutron scattering from vitreous silica in the frequency range 0.3 to 4 THz and with scattering vectors in the range 0.2 to 5.3 A${\r{}}^{\mathrm{\ensuremath{-}}1}$ are analyzed in conjunction with heat-capacity measurements on the same samples to provide a microscopic description of low-frequency vibrational modes. The results show that additional harmonic excitations coexist with sound waves below 1 THz, and that these excitations correspond to relative rotation of ${\mathrm{SiO}}_{4}$ tetrahedra.