1970/10/01 by R J Bell, R. J. Bell, P. Dean +2 · 1 citation
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Glass properties and applications #Mineralogy and Gemology Studies #Photonic Crystals and Applications
paper · doi:10.1088/0022-3719/3/10/013
crossref issued 1970/10/01 · crossref published 1970/10/01 · crossref published-print 1970/10/01 · openalex publication_date 1970/10/01 · crossref published-online 2001/03/14 · crossref created 2002/07/26 · crossref deposited 2020/04/10 · openalex created_date 2025/10/10 · crossref indexed 2026/07/29 · openalex updated_date 2026/07/30
The authors previously (1968) presented vibrational spectra for vitreous silica, germania and beryllium fluoride, calculated from atomic arrangements in physical models based on the random network theory. The present work describes the localization properties of the normal modes of vibration. It is shown that the vibrations are, on the whole, less extended in space than the plane wave-like modes which characterize regular crystals. Localization tends to be greatest at high frequencies and, especially, near band edges. If nonbridging oxygen atoms are present in the structure, the spectra of vitreous silica and germania exhibit an additional band of very intense localization; atomic motions associated with modes in this band are effectively restricted to no more than a few atoms.