X-ray diffraction peaks from misfit dislocations in double- and triple-crystal diffractometry

We propose a common description of the full widths at half maximum of X‐ray diffraction peaks obtained in different scans of triple‐crystal diffractometry and as well as for glancing incidence and glancing exit double‐crystal measurements. Calculations are compared with measurements of GaAs/Si(001) heteroepitaxial films. We show that the diffraction peak broadening is entirely due to random 60° misfit dislocations that provide only a minor part of the misfit relaxation. The remaining relaxation is due to periodic edge misfit dislocations that do not contribute to the peak broadening. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)