We have decided to discontinue the publication of preprints on our preprint server end of 2024. The publication culture within mathematics has changed so much due to the rise of repositories such as ArXiV (www.arxiv.org) that we are encouraging all institute members to make their preprints available there. An institute's repository in its previous form is, therefore, unnecessary. The preprints published to date will remain available here, but we will not add any new preprints here.
We present a model based on continuum elasticity and energy minimization for the study of ferroelastic domain walls close to a surface. We focus on walls orthogonal to the surface, and predict a double-peak structure in the surface values of the squared elastic strain, which is directly related to the chemical reactivity. We also compute the height profile, which can be measured, in principle, e.g. with AFM, and the strain distribution in the bulk. Our results are in good agreement with previous atomistic simulations, which had required much bigger computational effort. Our approach is also used to explore the effect of the cubic anisotropy (C12/C11) on the surface structure of the intersection between the twin wall and the crystal surface.