Sokolović, I., Schmid, M., Diebold, U., & Setvin, M. (2019). Incipient ferroelectricity: A route towards bulk-terminated SrTiO₃. Physical Review Materials, 3(3), Article 034407. https://doi.org/10.1103/physrevmaterials.3.034407
General Materials Science; Ferroelectricity; Electronic Structure
en
Abstract:
An investigation of bulk-terminated (001) surfaces of SrTiO₃, a prototypical cubic perovskite, was made
possible with a novel cleaving procedure. Controlled application of strain on a SrTiO₃ single-crystal results
in a flat cleavage with μm-size domains of SrO and TiO₂. Distribution of these two terminations is dictated by
ferroelectric domains induced by strain during the cleavage process. Atomically resolved scanning tunneling
microscopy/atomic force microscopy measurements reveal the presence of point defects in a well-defined
concentration of (14 ± 2)%; Sr vacancies form at the SrO termination and complementary Sr adatoms appear
at the TiO₂ termination. These intrinsic defects stabilize the surface by balancing the interplay between
ferroelectricity, surface polarity, and surface charge
