Application of the statistical dynamical theory to gamma-ray diffraction experiments on low-dislocation quartz single crystals.

Abstract

Highly monochromatic (Deltalambda/lambda = 10(-6)) short-wavelength (lambda = 0.03 Å) gamma radiation has been used in the study of the diffraction processes in real single crystals. Dislocation-free silicon crystals and quartz crystals with small concentrations of chaotically distributed dislocations were investigated. The experimental results were processed with use of statistical dynamical theories of diffraction, both fundamental and advanced. It is shown that the advanced version is more reliable in both cases. However, the values of the average lattice phase E, describing the long-range distortions of the lattice, can differ markedly from the value of 1 for quartz crystals, and parameter L = -ln(E) has a square dependence on the extinction length.