We present the full in-plane phonon dispersion of graphite obtained from inelastic x-ray scattering, including the optical and acoustic branches, as well as the mid-frequency range between the K and M points in the Brillouin zone, where experimental data have been unavailable so far. The existence of a Kohn anomaly at the K point is further supported. We fit a fifth-nearest neighbour force-constants model to the experimental data, making improved force-constants calculations of the phonon dispersion in both graphite and carbon nanotubes available.
@article{arxiv.0705.2418,
title = {The phonon dispersion of graphite by inelastic x-ray scattering},
author = {M. Mohr and J. Maultzsch and E. Dobardzic and S. Reich and I. Milosevic and M. Damnjanovic and A. Bosak and M. Krisch and C. Thomsen},
journal= {arXiv preprint arXiv:0705.2418},
year = {2009}
}