The connection between energy and wavelength in, for example, crystal oscillations, termed the phonon dispersion relation, is a complicated function. The shape of the dispersion curve is, however, characteristic for a crystal, and mapping this affords valuable information on the properties of materials. As early as in 1955 Brockhouse and A.T. Stewart reported results concerning phonons in, among other things, aluminium crystals, and they specified for the first time an experimentally measured dispersion curve for these. In crystals of magnetic material, e.g. magnetite, a type of collective wave motion can occur among the atomic elementary magnets. This wave motion can be excited by neutrons, and Brockhouse was the first to study and measure the dispersion curve for the elementary excitations of this wave motion, termed magnons.
Neutrons make it possible to follow the change of atomic structures over time.
In the same way, his experiments with liquid lead provided a model for others to follow. Such experiments provided the starting point for a lively development of theories for liquids and non-ordered systems in general. Phenomena such as lattice dynamics and diffusion underwent a renaissance through these and subsequent research contributions. An important example is the ceramic superconductors now being studied intensively, although these have not yet been developed for commercial use.