Determination of the phonon dispersion of zinc blende „3C... silicon carbide by inelastic x-ray scattering

We present an experimental and theoretical investigation of the phonon dispersion relations in zinc blende (3C) SiC. The experimental data were obtained for the entire Brillouin zone by inelastic x-ray scattering ~IXS! using a synchrotron radiation source. Eigenvector analysis is performed with the aid of state-of-the-art linear response first principles calculations based on density functional theory. The theoretical predictions reproduce the experimental phonon dispersion remarkably well. These results are compared with data obtained previously for the ^111& direction by Raman spectroscopy using several SiC polytypes and the backfolding technique. IXS data for 4H modification along the c axis are also reported. © 2002 American Institute of Physics. @DOI: 10.1063/1.1484241#