Brillouin scattering determination of the whole set of elastic constants of a single transparent film of hexagonal symmetry

[object Object] Abstract. In this work it is shown that the Brillouin light scattering technique can be successfully applied for determining the five effective elastic constants of a single transparent film of hexagonal symmetry, in the micron range of thicknesses. Measurements have been performed on a polycrystalline ZnO film. about 1.3 pm thick. supported by a Si substrate. A major result of this work is thal the elastic constant c66 is selectively determined for the first time from detection of the shear horizontal mode travelling parallel to the film surface. Similarly, a selective determination of CII is attained from observation of the longitndinal mode guided by the film. The three remaining elastic constants, namely e ~ 3 ,e) ) and ca. can be then obtained hom detection of the Rayleigh surface mode and of the longitudinal bulk wave propagating ai different angles from the surface n o d .