Abstract

Phonon dispersion and lifetime are important data in order to model the electron-phonon coupling in superconductors. The standard technique for such measurements, inelastic neutron scattering, requires large volume single crystals, which are not always available. In particular, this is often the case for newly synthesised compound. Recently, inelastic x-ray scattering (IXS) has emerged as a possible alternative, effective even with sample sizes of few tens of microns. We will show the results obtained using IXS in selected systems, such as electron-doped and hole doped perovskite cuprate and MgB$_2$. We will draw a comparison between the high Tc compounds and the phonon mediated superconductors, in order to unveil the controversial role of phonon anomalies in the former. We will also discuss the complementarity between inelastic x-ray scattering and inelastic neutron scattering spectroscopies for such kind of investigations.