2006/02/06 by Spyros N. Yannopoulos, S. N. Yannopoulos, K. S. Andrikopoulos +3
Chemistry · Materials Science · Physics and Astronomy · #Atomic physics #Boson #Chemistry #Condensed matter physics #Density matrix #Glass properties and applications #Heat capacity #Inelastic neutron scattering #Inelastic scattering #Material Dynamics and Properties #Phase-change materials and chalcogenides #Physics #Quantum mechanics #Scattering #cond-mat.dis-nn #cond-mat.soft
paper · pdf · doi:10.1016/j.jnoncrysol.2006.02.164
To appear in J. Non-Cryst. Solids (Proceedings of the 5th IDMRCS, Lille, July 2005)
arxiv created 2006/02/06 · openalex publication_date 2006/08/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Implications of reduction procedures applied to the low energy part of the vibrational density of states in glasses and supercooled liquids are considered by advancing a detailed comparison between the excess - over the Debye limit - vibrational density of states g(w) and the frequency-reduced representation g(w)/w2 usually referred to as the Boson peak. Analyzing representative experimental data from inelastic neutron and Raman scattering we show that reduction procedures distort to a great extent the otherwise symmetric excess density of states. The frequency of the maximum and the intensity of the excess experience dramatic changes; the former is reduced while the latter increases. The frequency and the intensity of the Boson peak are also sensitive to the distribution of the excess. In the light of the critical appraisal between the two forms of the density of states (i.e. the excess and the frequency-reduced one) we discuss changes of the Boson peak spectral features that are induced under the presence of external stimuli such as temperature (quenching rate, annealing), pressure, and irradiation. The majority of the Boson peak changes induced by the presence of those stimuli can be reasonably traced back to simple and expected modifications of the excess density of states and can be quite satisfactorily accounted for the Euclidean random matrix theory. Parallels to the heat capacity Boson peak are also briefly discussed.