Dispersion of localized elastic modes in thin supported gold layers measured by Brillouin scattering

Abstract

The dispersion of higher-order localized elastic modes of gold layers on glass has been measured by Brillouin scattering. For layer thicknesses h≥100 Å the dispersion of the sound velocities is well described by elastic continuum theory, whereas for h<100 Å deviations occur due to island formation. The results yield a reliable, nondestructive method to determine either elastic constants and mass density or the thickness of thin supported metal layers.