Low-frequency Raman scattering from small silver particles embedded in SiO 2 thin films

摘要: Intense, low-frequency Raman scattering from localized acoustic vibrations of small, spherical Ag particles embedded in ${\mathrm{SiO}}_{2}$ thin films has been observed. It was found that the peak shifts to higher frequencies as particle size decreases. For smaller than 4 nm, dependence frequency can be well explained by Lamb's theory, which gives vibrational a homogeneous elastic body with form. The observed is relatively strong and believed enhanced excitation surface plasmons particles; enhancement mechanism analogous case surface-enhanced molecules adsorbed on rough metal surfaces.