Mook has conducted neutron scattering research on a broad spectrum of materials. He is best known for his pioneering research on the magnetic excitations of transition metal ferromagnets and the observation of itinerant electron effects in these materials.
For outstanding contributions to many areas of solid-state physics, including the electronic structure of metals, ultrarapid melting and solidification phenomena, pulsed-laser deposition and epitaxial film growth, high-temperature superconductivity, and beam-assisted processing of thin films and superlattices.
For basic studies in the fracture of and toughening mechanisms in ceramics and ceramic composites, in the establishment of the relationships between microstructure and composition and mechanical behavior, and in the development of advanced ceramic materials.
For applying molecular beam techniques to study chemically reactive collisions, helping to lay the foundation for the present field of chemical dynamics, and for pioneering studies in accelerator-based atomic physics, ion-solid interactions, and the channeling of ions, electrons and positrons in crystalline solids.