Floppy modes in crystalline and amorphous silicates

M T Dove, Mark Harris, A C Hannon, J M Parker, I P Swainson, M Gambhir

Research output: Contribution to journalArticlepeer-review


We present the results of comparative inelastic neutron scattering measurements of both amorphous and crystalline silicates. We demonstrate the presence of floppy modes in amorphous silica and potassium disilicate over the energy scale 0–5 meV. A peak is also observed at 5 meV in amorphous silica, which is traditionally associated with the boson peak. By comparison with the spectrum of crystalline a-cristobalite, we show that it, in fact, arises from the transverse acoustic modes. The same peak in amorphous potassium disilicate cannot be resolved because it is obscured by a large number of floppy modes. [S0031-9007(96)02212-0]
Original languageEnglish
Pages (from-to)1070-1073
Number of pages4
JournalPhysical Review Letters
Issue number6
Publication statusPublished - 10 Feb 1997


Dive into the research topics of 'Floppy modes in crystalline and amorphous silicates'. Together they form a unique fingerprint.

Cite this