X-Ray Integrated Intensity of Germanium Effect of Dislocations and Chemical Impurities

Abstract

The absolute values of x-ray integrated intensities from germanium single crystals were measured with CuKα radiation. Dislocation densities below 105 cm−2 did not significantly affect intensities for the first three orders of (111). The observed absolute intensities of all reflections agreed with the prediction of the Darwin-Prins theory within the estimated errors of the measurements and the theoretical calculations. To investigate the effect of chemical impurities on intensities, crystals with one part in 104 of indium or lithium atoms and less than 105 dislocations/cm2 were studied. Regions of the indium doped specimen had (444) intensities 30% higher than the high resistivity specimens, while the crystals in which lithium had precipitated gave an increase of about 40% for this reflection. The precipitated lithium broadened the reflection curves and produced a diffuse scattering in the neighborhood of the Bragg reflection. It is presumably the strains caused by the impurity atoms that are responsible for the increased intensity.