Spatially resolved twin domain distribution and lattice parameter variations in the near-surface region of SrTiO single crystals.

We investigated the twin domain distribution and lattice parameter variations associated with the displacive phase transition in SrTiO by means of X-ray diffraction with high spatial resolution. By using 4.5-keV photons, the probed region is the first micrometer near the surface. We find a very inhomogeneous domain distribution, showing both regions with large monodomains and highly twinned regions, as well as large needle domains. Also, the lattice parameters in these different regions vary substantially. [ABSTRACT FROM AUTHOR]