Sound attenuation in an unexplored frequency region: Brillouin Ultraviolet Light Scattering measurements in v-SiO2

TL;DR

This study presents ultraviolet Brillouin light scattering measurements on v-SiO2 in a previously unexplored frequency range, revealing temperature-dependent attenuation behavior and a possible transition to different attenuation regimes.

Contribution

It provides new experimental data on v-SiO2 at high wavevectors using UV Brillouin scattering, highlighting a q^2 attenuation behavior and a crossover in attenuation mechanisms.

Findings

Attenuation scales with q^2 and depends on temperature.

Data suggests a dynamic attenuation mechanism dominates.

Evidence of a crossover to different attenuation regimes.

Abstract

We report Ultraviolet Brillouin light scattering experimental data on v-SiO2 in an unexplored frequency region, performed with a newly available spectrometer up to exchanged wavevector q values of 0.075 nm^{-1}, as a function of temperature. The measured attenuation scales on visible data following a q^2 behavior and is temperature-dependent. Such temperature dependence is found in a good agreement with that measured at lower q, suggesting that its origin is mainly due to a dynamic attenuation mechanism. The comparison between the present data with those obtained by Inelastic X-ray Scattering suggests the existence of a cross-over to a different attenuation regimes.