Lattice dynamics of α-cristobalite and the Boson peak in silica glass. (14th July 2015)

• Record Type: Journal Article
• Authors: Wehinger, Björn; Bosak, Alexeï; Refson, Keith; Mirone, Alessandro; Chumakov, Aleksandr; Krisch, Michael
• Is Part Of: Journal of physics. Volume 27:Number 30(2015)
• Publication Date: 2015-07-14
• Subjects: cristobalite -- lattice dynamics -- Boson peak -- silica polymorph -- silica glass -- phonon dispersion -- inelastic scattering; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/30/305401
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: The lattice dynamics of the silica polymorph -cristobalite has been investigated by a combination of diffuse and inelastic x-ray scattering and ab initio lattice dynamics calculations. Phonon dispersion relations and vibrational density of states are reported and the phonon eigenvectors analyzed by a detailed comparison of scattering intensities. The experimentally validated calculation is used to identify the vibration contributing most to the first peak in the density of vibrational states. The comparison of its displacement pattern to the silica polymorphs -quartz and coesite and to vitreous silica reveals a distinct similarity and allows for decisive conclusions on the vibrations causing the so-called Boson peak in silica glass.