H. R. Schober

Anharmonicity, vibrational instability, and the Boson peak in glasses

We show that a vibrational instability of the spectrum of weakly interacting quasilocal harmonic modes creates the maximum in the inelastic scattering intensity in glasses, the Boson peak. The instability, limited by anharmonicity, causes a complete reconstruction of the vibrational density of states (DOS) below some frequency

Kinetics of the high- to low-density amorphous water transition

{\ensuremath{\omega}}_{c},

Structure and relaxation in liquid and amorphous selenium

proportional to the strength of interaction. The DOS of the new harmonic modes is independent of the actual value of the anharmonicity. It is a universal function of frequency depending on a single parameter \char22{} the Boson peak frequency

Low-frequency vibrations and relaxations in glasses

{\ensuremath{\omega}}_{b}

Ice XII in Its Second Regime of Metastability

which is a function of interaction strength. The excess of the DOS over the Debye value is

Diffusion and jump-length distribution in liquid and amorphous Cu 33 Zr 67

\ensuremath{\propto}{\ensuremath{\omega}}^{4}

Pressure dependence of the boson peak in glasses

at low frequencies and linear in

Low Energy Excitations in Glasses and Melts

\ensuremath{\omega}

Localized relaxations in glasses

in the interval

Size effects and quasilocalized vibrations

{\ensuremath{\omega}}_{b}\ensuremath{\ll}\ensuremath{\omega}\ensuremath{\ll}{\ensuremath{\omega}}_{c}.