Observation of the Raman scattering by acoustic vibrations of fractal voids

The Raman scattering by acoustic vibrations of the fractal units is well st udied for nanoscopic solid fractals vibrating in vacuum. This work gives ev idence of the existence of a similar effect but involving the vibrations of closed fractal nanocracks propagated in a dense medium (vitreous SiO2). Th e fracton spectrum was found to be sensitive to both crack size and compact ness of the crack wall material.