This important book presents a comprehensive account of the techniques and applications of single crystal neutron diffraction in the area of chemical crystallography and molecular structure. Beginning with a brief description of the general principles and the reasons for choosing the technique — the “why” — the book covers the methods for both the production of neutrons and the measurement of their scattering by molecular crystals — the “how” — followed by a detailed survey of past, present and future applications — the “what”. The coverage of both steady state and pulsed neutron sources and instrumentation is extensive, while the survey of applications is the most comprehensive yet undertaken. The book endeavours to show why the technique is an essential method for studying areas as diverse as hydrogen bonding and weak interactions, organometallics, supramolecular chemistry and crystal engineering, metal hydrides, charge density and pharmaceuticals. It is an ideal reference source for the research worker interested in using neutron diffraction to study the structure of molecules.

The neutron total cross section of a single crystal of Si was studied over the energy range 0.003 eV to 50 eV at the Weapons Neutron Research Facility (WNR). The neutron energies were determined by time of flight. The 28.77 cm long Si sample was held at three temperatures, 296K, 77K, and 20°K. The 21°K temperature was obtained by filling an encircling cryostat with liquid H2. The region of greatest interest is below 1 eV where Bragg scattering from the perfect crystal is small and where thermal diffuse scattering can be reduced by cooling the Si. Near 0.05 eV the cross section dips to less than 1/5 its value at energies greater than 1 eV. This feature has allowed single crystals of Si to be used very successfully as thermal neutron band pass filters. Data at 296K and 77°K agree with previous measurements. Very little structure caused by Bragg scattering is observed. Measured cross sections for 21°K are somewhat below the 77°K data but not enough lower to justify cooling a Si filter to 21°K to dramatically improve its transmission.

This is the first comprehensive account of diffuse neutron scattering, a unique tool for determining structural disorder in solids. The text takes the reader through theoretical, computational and experimental developments in the subject and describes in detail its application to a number of structural disorder problems. These include the more traditional subjects of substitutional disorder in alloys and orientational disorder in molecular systems as well as the more recent studies of superior and framework materials. Particular emphasis is placed on recent refinement methods for data interpretation and these are compared with established computer simulation techniques and analytical approaches. The book collects disparate themes into one unique volume, which is written as an introduction to the methods for graduate scientist and as a valuable reference or the expert crystallographer who wishes to apply modern interpretative techniques to diffuse scattering data.

This is the first book covering the theory, practicalities, and the extensive applications of neutron powder diffraction in materials science, physics, chemistry, mineralogy and engineering. Various highlight applications of neutron powder diffraction are outlined in the introduction, then the theory is developed and instrumentation described sufficient for a return to the applications. The book covers the use of neutron powder diffraction in the solution (hard) and refinement (more straightforward) of crystal and magnetic structures, applications of powder diffraction in quantitative phase analysis, extraction of microstructural information from powder diffraction patterns, and the applications of neutron diffraction in studies of elastic properties and for the measurement of residual stress. Additional theory to underpin these various applications is developed as required. Much of the material should be accessible to senior undergraduates in science and engineering, as well as to graduate students and more senior researchers with an interest in the technique.