Low frequency vibrational density of state of highly permeable super glassy polynorbornenes – the Boson peak

2020 ◽  
Vol 22 (33) ◽  
pp. 18381-18387
Author(s):  
Reiner Zorn ◽  
Paulina Szymoniak ◽  
Mohamed A. Kolmangadi ◽  
Marcell Wolf ◽  
Dmitry A. Alentiev ◽  
...  
Keyword(s):  
Density Of States ◽  
Time Of Flight ◽  
Low Frequency ◽  
Boson Peak ◽  
Density Of State ◽  
Neutron Time ◽  
Incoherent Neutron ◽  
Vibrational Density

Inelastic incoherent neutron time-of-flight scattering was employed to measure the low frequency density of states for a series of addition polynorbornenes with bulky side groups.

scholarly journals Anomalies in the low frequency vibrational density of states for a polymer with intrinsic microporosity – the Boson peak of PIM-1

2018 ◽  
Vol 20 (3) ◽  
pp. 1355-1363 ◽  
Author(s):  
Reiner Zorn ◽  
Huajie Yin ◽  
Wiebke Lohstroh ◽  
Wayne Harrison ◽  
Peter M. Budd ◽  
...  
Keyword(s):  
Density Of States ◽  
Low Frequency ◽  
Boson Peak ◽  
Vibrational Density Of States ◽  
First Time ◽  
Intrinsic Microporosity ◽  
Vibrational Density

For the first time the low frequency vibrational density of states is reported for a polymer with intrinsic microporosity.

The origin of the anomalous low-frequency vibrational behaviour of amorphous solids

1992 ◽  
Vol 02 ◽  
pp. C2-279-C2-283
Author(s):  
S. R. ELLIOTT
Keyword(s):  
Low Frequency ◽  
Peak Frequency ◽  
Amorphous Solids ◽  
Boson Peak ◽  
Low Frequencies ◽  
Crystalline Materials ◽  
Medium Range ◽  
Phonon Localization ◽  
Strong Scattering ◽  
Vibrational Density

The anomalous vibrational behaviour exhibited by non-crystalline materials - a peak in the vibrational density of states, and in the Raman spectrum (the boson peak) at low frequencies, and a peak in the heat capacity and a plateau in the thermal conductivity at low temperatures - is ascribed ta phonon localization associated with the strong scattering of phonons by density-fluctuation domains in the structure. Within such domains, short-range and medium-range arder is maintained, and outside them the material is structurally homogeneous and isotropie. This model can also explain the correlation between the boson-peak frequency and the position of the first sharp diffraction peak in the structure factor observed in a number of inorganie and polymerie amorphous solids.

Intramolecular low-frequency vibrations in lysozyme by neutron time-of-flight spectroscopy

Biopolymers ◽  
1982 ◽  
Vol 21 (1) ◽  
pp. 43-50 ◽  
Author(s):  
H. D. Bartunik ◽  
P. Jollès ◽  
J. Berthou ◽  
A. J. Dianoux
Keyword(s):  
Time Of Flight ◽  
Low Frequency ◽  
Neutron Time ◽  
Time Of Flight Spectroscopy

scholarly journals Применение теории случайных матриц для описания бозонного пика в двумерных системах

2020 ◽  
Vol 62 (4) ◽  
pp. 603
Author(s):  
Д.А. Конюх ◽  
Я.М. Бельтюков
Keyword(s):  
Density Of States ◽  
Disordered Systems ◽  
Degrees Of Freedom ◽  
Matrix Theory ◽  
Three Dimensional ◽  
Amorphous Solids ◽  
Boson Peak ◽  
Two Dimensional ◽  
Reduced Density ◽  
Vibrational Density

The random matrix theory is applied to describe the vibrational properties of two-dimensional disordered systems with a large number of degrees of freedom. It is shown that the most significant mechanical properties of amorphous solids can be taken into account using the correlated Wishart ensemble. In this ensemble, an excess vibrational density of states over the Debye law is observed as a peak in the reduced density of states g(ω)/ω. Such a peak is known as the boson peak, which was observed in many experiments and numerical simulations for two-dimensional and three-dimensional disordered systems. It is shown that two-dimensional systems have a number of differences in the asymptotic behavior of the boson peak.

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