Brillouin light scattering on chemical-vapor-deposited polycrystalline diamond: Evaluation of the elastic moduli

Abstract
We report on Brillouin light scattering investigations on chemical‐vapor‐deposited polycrystalline diamond films. Besides the longitudinal and two transverse acoustic bulk phonons, a Rayleigh surface mode is observed. From the bulk modes the elastic constants c11, c12, and c44 of 1062±74, 122±8, and 541±22 GPa, respectively, are determined exhibiting the characteristic values of natural diamond. The observed Rayleigh mode sound velocity of 10326±470 m/s is consistent with the (110) texture of the polycrystalline film and the determined elastic constants.