title: Lattice dynamics of α-cristobalite and the Boson peak in silica glass.
abstract: The lattice dynamics of the silica polymorph [Formula: see text]-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 [Formula: see text]-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.
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24, Quai Ernest Ansermet, CH-1211 Genève, Switzerland. Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
authors.forename: Björn
authors.initials: B
authors.lastname: Wehinger
authors.forename: Alexeï
authors.initials: A
authors.lastname: Bosak
authors.forename: Keith
authors.initials: K
authors.lastname: Refson
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mirone
authors.forename: Aleksandr
authors.initials: A
authors.lastname: Chumakov
authors.forename: Michael
authors.initials: M
authors.lastname: Krisch