The measurement of defect parameters in imperfect crystals using X-ray diffraction

Abstract

Correlation lengths and defect-strength parameters, related to the separations and magnitudes of discontinuities in imperfect crystals, are obtained from X-ray rocking curves using a stochastic model of crystal defects. The model describes the diffraction of X-rays from an imperfect crystal containing surfaces of defects, such as stacking faults, and misoriented crystal grains. The two defect parameters provide a measure of crystal quality. A method of extracting the parameters from rocking curves is described in the limit of kinematic X-ray diffraction. The method is applied to X-ray diffraction data obtained from thin films of CdTe and Hg 1-x Cd x Te grown on GaAs substrates. The ability of the model to fit the X-ray data is a test of the stochastic model