Title: Neutron scattering investigations of the boson peak
Author(s):

U. Buchenau (Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany)

Inelastic neutron scattering is not only capable of determining a generalized vibrational density of states around the boson peak of a glass, but can also be used to get information on the eigenvectors. The eigenvectors determine the dynamic structure factor, which is Q²S(Q) (Q wavevector) for long wavelength sound waves. This enables the determination of the sound wave fraction below and at the boson peak, done for SiO₂, B₂O₃, polybutadiene and amorphous germanium. The temperature dependence of the boson peak in silica and glycerol is shown. X-ray Brillouin scattering data show that the damping of the longitudinal sound waves in silica and glycerol follows the soft potential model ω⁴ prediction in the limit of low frequency.

Key words: glasses, inelastic neutron scattering, boson peak
PACS: 61.20.Lc, 61.43.Fs, 61.12.Ex

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