Brillouin scattering investigation of melting in Sn nanoparticles

The abrupt change of velocity in surface acoustic waves in thin films of amorphous SiOx containing nanometre scale β-Sn crystals has been shown to be directly associated with the size-dependent melting of the nanoparticles. Effective medium theory has been used to explain the origin and the magnitude of the anomaly. A central peak in the Brillouin spectrum, whose intensity showed a maximum at the melting temperature, can be interpreted in terms of overdamped fluctuations in the dielectric function.