X-ray diffraction from dislocation half-loops consisting of a misfit segment
and two threading arms extending from it to the surface is calculated by the
Monte Carlo method. The diffraction profiles and reciprocal space maps are
controlled by the ratio of the total lengths of the misfit and the threading
segments of the half-loops. A continuous transformation from the diffraction
characteristic of misfit dislocations to that of threading dislocations with
increasing thickness of an epitaxial film is studied. Diffraction from
dislocations with edge and screw threading arms is considered and the
contributions of both types of dislocations are compared