Kinematical diffraction intensity as a function of excitation error, or a rocking curve, observed from a crystal, which has a displacement field inhomogeneous along the incident beam direction, z, is obtained by an absolute square of lattice scattering amplitude € φ g given by the following formula,where t, s and R(z) indicate specimen thickness, excitation error and displacement vector of the strained lattice, respectively, and A(z) is unity for 0 < z < t and zero for z < 0 or z > t. The z-axis is along the beam direction and its origin is set to be at the specimen surface. This formula shows thatby Fourier transform. The Fourier iterative phase retrieval has been applied to reconstruct the phase of € φ g , and thus, phase factor € α = −2πig ⋅ R(z) with an real space constraint of A(z) [1]. In the present study, the z-dependence of the 3D lattice displacement field R(z) was determined by the Fourier iterative phase retrieval of rocking curve profiles of mutually independent reflections. A Si 0.7 Ge 0.3 layer of a 50 nm thickness was deposited on a silicon substrate of (110) plane by the molecular beam epitaxy technique. The specimen for the CBED experiment was prepared by ion thinning. Fig. 1 shows a cross section TEM image of the specimen used for the present study. The CBED experiment was conducted at an acceleration voltage of 200 kV by using a field-emission transmission electron microscope, JEOL JEM-2100F equipped with an energy filtering system, Gatan GIF with a 2k x 2k CCD camera.