X-Ray and Neutron Pair Distribution Function Analysis

Pair distribution function (PDF) obtained by X-ray diffraction (XRD) and neutron diffraction (ND) measurements enables us to probe the structure of disordered materials, which has no long-range order and periodicity. This chapter provides an introduction to PDF analysis using XRD and ND techniques. A brief outline of the theory of diffraction for disordered materials is given with a focus on the use of various real-space functions. The structures of single-component disordered materials are introduced to understand the origins of characteristic diffraction peaks, i.e., the first sharp diffraction peak (FSDP) and the principal peak (PP), observed in broad halo patterns. Furthermore, the instrumentation of synchrotron X-rays and neutrons for PDF analysis with associated results for the structural studies of disordered materials under high temperature and high pressure are reviewed.