Glass-specific behavior in the damping of acoustic-like vibrations

TL;DR

This study investigates high-frequency sound behavior in lithium diborate glass, revealing a universal link between the boson peak and sound attenuation limits in strong glasses, suggesting a fundamental glass-specific vibrational property.

Contribution

It uncovers a universal correlation between the boson peak and Ioffe-Regel limit in strong glasses, highlighting a specific vibrational behavior unique to glassy materials.

Findings

Rapid increase in sound attenuation near the boson peak

Near coincidence of boson-peak frequency with Ioffe-Regel limit in strong glasses

Behavior likely universal among glassy materials

Abstract

High frequency sound is observed in lithium diborate glass, Li$_2$O--2B$_2$O$_3$, using Brillouin scattering of light and x-rays. The sound attenuation exhibits a non-trivial dependence on the wavevector, with a remarkably rapid increase towards a Ioffe-Regel crossover as the frequency approaches the boson peak from below. An analysis of literature results reveals the near coincidence of the boson-peak frequency with a Ioffe-Regel limit for sound in {\em all} sufficiently strong glasses. We conjecture that this behavior, specific to glassy materials, must be quite universal among them.