Inelastic neutron scattering is a well established and important technique for studying the dynamical properties of condensed matter at the atomic level. Often, as is the case of experiments designed to study motions of hydrogen atoms, or magnetic excitations, it may yield information obtainable in no other way. Our aim in assembling this book is to produce an overview of some research topics which have come to the fore recently with the development of high neutron fluxes and high performance inelastic scattering spectrometers. The topics dis­ cussed here are, by and large, developing rapidly and have not reached the stage at which definitive accounts are always possible. Authors have not therefore attempted to make an extensive review of their topic, and the papers quoted in the text are, in general, those which are seen as having been important in its develop­ ment (they date, roughly, from the 1971 IAEA conference on neutron scattering held in Grenoble). Basic phenomena are illustrated for the most part by the discussion of one, or two, typical examples. The authors hope that the book will be useful to researchers who are not yet fully aware of the diverse range of problems to which the technique can be applied, and to students beginning research work. For this reason, the first chapter by S. w.

1. Introduction.- 1.1 Prologue.- 1.2 Correlation Functions.- 1.3 Nuclear Scattering.- 1.4 Polarization Effects.- 1.5 Magnetic Scattering.- Appendix A: Crystal Lattices and Reciprocal Lattices.- References.- 2. Phonons.- 2.1 Lattice Dynamics and Neutron Scattering.- 2.2 Lattice Dynamics of Crystals of the Rutile Type - TiO2, MgF2, and MnF2.- 2.3 Phonon Anomalies in Superconducting Materials.- 2.4 Layered Compounds.- 2.5 Effects of Pressure on Phonon Spectra.- References.- 3. Phonons and Structural Phase Transformations.- 3.1 Relation Between Neutron and X-Ray Scattering Techniques.- 3.2 Fluctuations and Order.- 3.3 Experimental Results.- References.- 4. Dynamics of Molecular Crystals, Polymers, and Adsorbed Species.- 4.1 Molecular Crystals.- 4.2 Polymers.- 4.3 Structure and Dynamics of Adsorbed Species.- 4.4 Chemisorption.- 4.5 Intercalation Compounds.- 4.6 Conclusions.- References.- 5. Molecular Rotations, and Diffusion in Solids, in Particular Hydrogen in Metals.- 5.1 Diffusion in Solids, in Particular Hydrogen in Metals.- 5.2 Rotations in Molecular Solids.- 5.3 Liquids, Liquid Crystals, and Related Problems.- References.- 6. Collective Modes in Classical Monoatomic Liquids.- 6.1 Collective Modes.- 6.2 Coherent Scattering.- 6.3 Transverse Current Correlations.- 6.4 Relations Between S(Q,?) and Ss(Q,?).- 6.5 Current Issues.- References.- 7. Magnetic Scattering.- 7.1 Magnons in Ionic Compounds.- 7.2 Quasi One- and Two-Dimensional Systems.- 7.3 Magnons in Metals.- 7.4 Crystal Field Levels in Rare Earth Compounds.- 7.5 Magnons and Excitons in Rare Earth Metals.- 7.6 Critical Magnetic Scattering.- 7.7 Hyperfine Field Measurements.- References.