Neutron scattering study of the high-energy graphitic phonons in superconductingCaC6

M. P. M. Dean, A. C. Walters, C. A. Howard, T. E. Weller, M. Calandra, F. Mauri, M. Ellerby, S. S. Saxena, A. Ivanov, D. F. McMorrow
2010 Physical Review B  
We present the results of a neutron scattering study of the high energy phonons in the superconducting graphite intercalation compound CaC_6. The study was designed to address hitherto unexplored aspects of the lattice dynamics in CaC_6, and in particular any renormalization of the out-of-plane and in-plane graphitic phonon modes. We present a detailed comparison between the data and the results of density functional theory (DFT). A description is given of the analysis methods developed to
more » ... nt for the highly-textured nature of the samples. The DFT calculations are shown to provide a good description of the general features of the experimental data. This is significant in light of a number of striking disagreements in the literature between other experiments and DFT on CaC_6. The results presented here demonstrate that the disagreements are not due to any large inaccuracies in the calculated phonon frequencies.
doi:10.1103/physrevb.82.014533 fatcat:7tcc7sg7r5aftddtvfvojrqyzy