X-RAY-DIFFRACTION STUDIES OF MISCUT CRYSTAL-SURFACES AND OVERLAYERS -A DYNAMICAL DIFFRACTION APPROACH

X-ray surface diffraction data from a miscut Fe3Al crystal and the non -specular crystal-truncation rod of a monolayer Au on a Ge(111) surfac e are interpreted using the dynamical theory in relation to the struct ures of surface/interface of thin films and bulk crystals. It is found that in the miscut crystal the X-ray penetration depth depends on the crystal miscut angle due to the boundary effect on the excitation of mode of wave propagation. For the Au/Ge(111) case, the diffracted inte nsity must be summed up in a kinematical fashion to take account of th e scattering from the deposited overlayers. This dynamical calculation scheme provides an absolute scale for intensity versus momentum trans fer which is useful for surface-and thin film analysis.