Atomic Vibrations in Stressed Crystal Lattices by Inelastic Scattering of Neutrons

摘要

A scattering chamber for inelastic neutron scattering at pressures up to 3000 atm was constructed. This pressure proved to be large enough to induce in some materials phonon frequency shifts of the order of 1% which are measurable by the inelastic neutron scattering technique. Measurements on pressure induced frequency shifts of some phonons in lead and sodium iodide were made. The phonon frequency distribution in the random binary alloy Pt + Cu (5%) was compared with that of a pure Pt sample. Also measured was the change of phonon frequency distribution of very fine MgO powders against that of large-crystalline samples. (Author)