Studying Lattice Dynamics in Inorganic Materials by Inelastic Neutron Scattering

Inelastic neutron scattering is arguably the single most powerful technique for studying the dynamics of materials. We review the standard formalism for studying atomic vibrations in crystalline materials and outline how this can be expanded to treat disordered and amorphous solids. We describe how these vibrations can be probed using inelastic neutron scattering experiments; present the two major types of neutron spectrometer used for this purpose, time-of-flight and triple-axis instruments; and offer guidelines on how to select an instrument, prepare an experimental proposal, and interpret the results assisted by appropriate simulations. Finally, we compare inelastic neutron scattering to other varieties of vibrational spectroscopy. We illustrate these principles with case studies of several important inorganic materials studied by inelastic neutron scattering, including the soft-mode transitions in quartz and ferroelectrics; lithium-based materials for solid-state conduction; thermoelectrics; barocalorics, negative thermal expansion materials; and porous materials like zeolites and metal–organic frameworks.