The X-ray diffraction behaviour of tetragonal (orthorhombic) crystals which were twinned on the {011} plane was studied, in the kinematic approach, by means of computer simulations. It was assumed that the twin boundaries were not sharp, and it was demonstrated that the diffuse scattering intensity was determined not only by the twin-wall thickness but also by the twin-boundary density and by the degree of tetragonality (orthorhombicity) as well. A method for estimating the twin-wall thickness was proposed which was based upon the experimentally measured intensity distributions.

Peculiarities of X-Ray Diffraction in Crystals with Diffuse Twin Boundaries in the {011}, <011> System. A.I.Ustinov, J.C.Niepce, C.Valot, L.A.Olikhovska, F.Bernard: Materials Science Forum, 2000, 321-324, 109-14