X-Ray Measurement of Microstrains in Germanium Single Crystals

Abstract

The high intensity of the anomalously transmitted x‐ray beam depends upon the coincidence of the nodal planes of the x‐ray wave field with one set of atomic planes within the crystal when the crystal is set for Laue diffraction. If there is any structural defect within the crystal which causes some of the atoms of the crystal to deviate from their normal location in perfect planes, these atoms will no longer be at the nodes of the x‐ray wave field and by their absorption they will reduce the transmitted intensity. The present paper shows how this effect may be employed to measure the amount of microstrain present in nearly perfect germanium crystals. It is found that some apparently dislocation free crystals show a greater degree of crystalline imperfection than crystals with a finite dislocation count.