Phonon dispersion in the one-layer cuprate HgBa2CuO4+δ

We investigate the low energy acoustical and optical modes in HgBa2CUO4+delta using inelastic x-ray scattering (IXS). The experimental phonon dispersion and the dynamical structure factor are compared with an atomic shell model, and the set of atomic potentials obtained is discussed. Our results are also compared with those obtained by Raman spectroscopy and with density-of-state data measured by inelastic neutron scattering.