Elastic Spectrum of Zinc from the Temperature Scattering of X-Rays

Abstract

The temperature diffuse scattering of x-rays from a single crystal of zinc has been measured at room temperature using a Geiger counter spectrometer and crystal monochromated Cu $K\alpha$ radiation. The theory of Born, together with Begbie's theory of lattice dynamics for a hexagonal crystal, was used in the interpretation. A method was developed to separate the contributions to intensity from the acoustical and optical bands. Frequency curves for the six modes of vibration propagating parallel to the $b_3$ axis, and for the six modes propagating parallel to the $b_2$ axis were obtained. Measurements were in agreement with theory for long wavelength acoustical modes, but for shorter wavelengths the first neighbor theory was not in agreement with the measurements. Approximate values for seven of the eight nearest neighbor force constants were obtained, and these values could be used for the calculation of an approximate frequency distribution curve.