Measuring small lattice distortions in Si-crystals by phase-contrast x-raytopography

X-ray phase-contrast topography has been improved by using phase modulation and computing techniques to determine lattice distortions inside near-perf ect Si monocrystals. The technique presented is based on the detection of t he spatially varying phase shift at the output of a monolithic x-ray interf erometer of the triple Laue type using phase modulation and a multi-element detector. Information was obtained about the degree of perfection of cryst als being used in the determination of the (220) lattice plane spacing of s ilicon and of the Avogadro constant.