  We have studied the phonon density of states (PDOS) in LaFeAsO1-xFx with
inelastic neutron scattering methods. The PDOS of the parent compound(x=0) is
very similar to the PDOS of samples optimally doped with fluorine to achieve
the maximum Tc (x~0.1). Good agreement is found between the experimental PDOS
and first-principle calculations with the exception of a small difference in Fe
mode frequencies. The PDOS reported here is not consistent with conventional
electron-phonon mediated superconductivity.
