Steep slopes of the dynamical X-ray diffraction curves can be utilized for the determination of homogeneous elastic strains produced by electric potential, hydrostatic pressure etc. The principle of the new method is explained with some dynamical effects of the X-ray diffraction. The sensitivity is estimated by using the intrinsic rocking curves of the Bragg-case diffraction and is found to be suitable for the strains from 5×10-6 to 5×10-8 experimentally. A three-crystal spectrometer is convenient in the experimental procedure. Piezoelectric constants of α-quartz and KDP and also electrostrictive constant and linear compressibility of α-quartz were measured with the spectrometer.
Microdefects in Czochralski grown silicon single crystals have been investigated by transmission electron microscopy, infrared absorption spectroscopy, X-ray topography and etching technique. Swirl defects were identified as interstitial perfect dislocation loops and silicon oxide precipitates. Swirl oxide precipitates emit dislocation loops and stacking faults on thermal oxidation. Stacking fault growth was found to obey the Bardeen-Herring source mechanism, and to proceed through the absorption of silicon interstitials emitted by oxygen precipitation. Crystal growth under the supercooled condition is effective to suppress the defect introduction because growth rate fluctuation as well as oxygen dissolution from the quartz crucible are reduced.