Lattice dynamics of strontium and barium

The phonon dispersion curves of fcc Sr and bcc Ba at room temperature and at 100 K have been determined. Neutron time-of-flight spectra of polycrystalline samples over a wide range of $Q$ and $\omega$ have been measured. The spectra were analyzed in terms of Born-von Kármán models. In addition, the elastic constants were obtained from the low-frequency part of the spectra.