Surface acoustic wave velocity and elastic constants of cubic GaN

Abstract

We present high resolution Brillouin scattering measurements on cubic GaN layers grown on GaAs substrate. By using a suitable scattering geometry, scattering by surface acoustic waves was recorded for different azimuthal angles and the surface acoustic wave velocities were determined.The comparison of the experimental results with numerical simulations of the azimuthal dependence of the surface wave velocity shows good agreement and allowed us to determine a consistent set of elastic constants for c-GaN.