In- and out-of-plane longitudinal acoustic-wave velocities and elastic moduli in h-BN from Brillouin scattering measurements Auteur(s): Jimenez-Rioboo Rafael J., Artus Lluis, Cusco R., Taniguchi Takashi, Cassabois G., Gil B. (Article) Publié: Applied Physics Letters, vol. 112 p.051905 (2018) Texte intégral en Openaccess : Ref HAL: hal-01697455_v1 DOI: 10.1063/1.5019629 WoS: 000424053600017 Exporter : BibTex | endNote 6 Citations Résumé: The elastic constants of high-quality, single-crystal hexagonal boron nitride (h-BN) have been measured by means of high resolution Brillouin spectroscopy using a modified reflected light microscope. The sound propagation velocity in the c-axis direction and perpendicular to the c-axis have been obtained from the Brillouin frequency shift, with a proper account taken of the vast difference between the ordinary and extraordinary refractive indices recently reported in the highly anisotropic layered h-BN crystal. The elastic constants c11 and c33 obtained from the Brillouin experiments are somewhat lower than previous determinations based on inelastic x-ray measurements and confirm the overestimation of the h-BN elastic constants by ab initio calculations based on density functional perturbation theory in the local density approximation. |