Internal strain in elastically strained germanium and silicon - I. Longitudinal case

X-ray diffraction of "forbidden" reflections in elastically strained germanium and silicon shows that the four nearest neighbor bonds are not strained according to the strain tensor but rather keep their length almost unchanged because of the occurrence of an internal strain. Consequently the bond angles are changed. From the structure factor of the (600) reflection, this internal strain has been found to be in good quantitative agreement with theoretical calculations. © 1964 Springer-Verlag.