Depth Dependence of the Structural Phase Transition of SrTiO_3 Studied with \beta-NMR and Grazing Incidence X-ray Diffraction

摘要

We present an investigation of the near-surface tetragonal phase transitionin SrTiO3, using the complementary techniques of beta-detected nuclear magneticresonance and grazing-incidence X-ray diffraction. The results show a cleardepth dependence of the phase transition on scales of a few microns. Themeasurements support a model in which there are tetragonal domains forming inthe sample at temperatures much higher than the bulk phase transitiontemperature. Moreover, we find that these domains tend to form at highertemperatures preferentially near the free surface of the crystal. The detailsof the tetragonal domain formation and their depth/lateral dependencies arediscussed.