Inelastic X-ray scattering: phonon spectroscopy under the extreme conditions

Diffuse scattering in relaxor ferroelectrics: true three-dimensional mapping, experimental artefacts and modelling

Three-dimensional synchrotron diffuse scattering data for the prototypical ferroelectric relaxor are presented. A new parameterization of diffuse scattering in relaxors is given and a simple phenomenological picture is proposed to explain the unusual properties of the relaxor behaviour.