A Study of the Crystal Dynamics of Zinc

Abstract

A number of the normal modes of vibration of the anisotropic hexagonal metallic system of zinc have been studied through a determination of the dispersion relations by neutron inelastic scattering. Measurements carrying relatively small experimental errors have been made for directions in a single crystal which produce information about the motions of atoms within the basal planes, the motion of the basal planes acting as single units, and the motions of atoms perpendicular to the basal planes which tend to warp these planes. Attempts are made to fit the experimental data to formulations of Born-von Kármán dynamical theory involving generalized forces between pairs of atoms. Consideration of forces extending to fourth nearest neighbors is necessary to obtain agreement with our dispersion relations. The experimental data generally supply details of the anisotropic mechanisms operating in zinc and indicate that anomalies might exist in the dispersion relations describing atomic motions perpendicular to the basal planes.