Phonon density of states of LaFeAsO(1-x)Fx

Phys Rev Lett. 2008 Oct 10;101(15):157004. doi: 10.1103/PhysRevLett.101.157004. Epub 2008 Oct 8.

Abstract

We have studied the phonon density of states (PDOS) in LaFeAsO(1-x)Fx 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 approximately 0.1). Good agreement is found between the experimental PDOS and first-principles 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.