Vibrational spectra of selenium nanoparticles dispersed in a polymer

Vibrational spectra of selenium nanoparticles dispersed in a polymer are st udied using Raman scattering. Confined optical and acoustic phonons are inv estigated. Asymmetric line-shape of the confined optical phonons is fitted using the confinement model which takes into account the phonon dispersion curves. A wavelength selectivity of confined optical phonons is also observ ed. The low frequency Raman spectrum exhibits peaks that can be assigned to the spheroidal modes of the particles of size around 3 nm, consistent with that used for confined optical phonon line-shape analysis. (C) 1999 Acta M etallurgica Inc.