5 - Structural characterisation of hydride materials

Abstract

Publisher Summary For studying hydrogen storage materials, both neutron and X-ray diffraction are important, but, in particular, neutron scattering techniques play a crucial role because of the significant scattering from hydrogen atoms. The field of crystallography and diffraction studies of crystalline materials has developed significantly during the past 10-20 years. This is both due to improved sources for X-rays and neutrons and because of significant improvements in the tools used to analyze diffraction data. Since hydrides normally exist as powdered samples, powder diffraction methods, with both X-rays and neutrons, are the main methods of finding their atomic arrangements. However, powder diffraction is also important to determine information about phase compositions, crystallite sizes, strain, and defects. This chapter describes diffraction, particularly X-ray and neutron diffraction, with an emphasis on the powder diffraction techniques. It presents the specific properties of X-ray and neutron diffraction and describes the sources and instruments for powder diffraction studies. Furthermore, it discusses the use of powder diffraction data, from the simple use for phase identification to structure solution and refinements with the Rietveld methods, and presents two examples showing the potential for powder diffraction, followed by a description of future trends.