Diffuse scattering and the local structure of relaxors*

Anomalous dielectric and electromechanical properties make relaxor ferroelectrics fundamentally and technologically appealing. We have used three dimensional diffuse scattering measurements (x-ray and neutron) to investigating several classes of relaxor ferroelectrics, including pseudo-cubic Pb-based perovskites and uniaxial tungsten bronze systems. We discuss the different components that are observed in these measurements and how they relate to the physics and material properties of these systems.