Brillouin Scattering from Metallic Ta/Al Fibonacci Multilayers

Surface phonon spectra from Ta/Al Fibonacci multilayers are studied via Brillouin scattering. Determination of the frequency positions of the Rayleigh wave and the intensity dip corresponding to the longitudinal threshold has enabled us to extract two effective elastic constants C₄₄ and C₁₁ of the whole structure. The 22.6% enhancement of the shear modulus is found in our experiment.