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I. Sokolovic, M. Schmid, U. Diebold, M. Setvin:
"Incipient ferroelectricity: A route towards bulk-terminated SrTiO₃";
Physical Review Materials, 3 (2019), 0344071 - 0344075.

An investigation of bulk-terminated (001) surfaces of SrTiO3, a prototypical cubic perovskite, was madepossible with a novel cleaving procedure. Controlled application of strain on a SrTiO3single-crystal resultsin a flat cleavage withμm-size domains of SrO and TiO2. Distribution of these two terminations is dictated byferroelectric domains induced by strain during the cleavage process. Atomically resolved scanning tunnelingmicroscopy/atomic force microscopy measurements reveal the presence of point defects in a well-definedconcentration of (14±2)%; Sr vacancies form at the SrO termination and complementary Sr adatoms appearat the TiO2termination. These intrinsic defects stabilize the surface by balancing the interplay betweenferroelectricity, surface polarity, and surface charge.

http://dx.doi.org/10.1103/PhysRevMaterials.3.034407