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O: Fachverband Oberflächenphysik
O 44: Focus Session: Surfaces and Interfaces of (Incipient) Ferroelectrics (joint session O/KFM)
O 44.3: Talk
Wednesday, September 7, 2022, 16:00–16:15, H3
Influence of Nb dopants on the polarization and screening on cleaved SrTiO3(001) surfaces — •Igor Sokolović1, Alexander Hoheneder1, Jesus Redondo2, Dominik Wrana2, Michael Schmid1, Ulrike Diebold1, and Martin Setvín2 — 1Institute of Applied Physics, TU Wien, Vienna, Austria — 2Faculty of Physics and Mathematics, Charles University, Prague, Czech Republic
The incipient ferroelectric SrTiO3 can turn ferroelectric even at room temperature under the application of strain, and this quantum phase transition can be utilized to cleave SrTiO3 single crystals that otherwise posses no preferable cleavage planes [1]. This cleaving procedure creates truly bulk-terminated SrTiO3(001) surfaces that come the closest to being pristine [2]. In this talk, I will present how the SrO- and TiO2-terminated surface domains of opposite polarity can be influenced by the small changes in the amounts of Nb doping. The cleaved SrTiO3(001) surfaces with varying Nb doping levels were systematically studied with atomic resolution using noncontact atomic force microscopy (ncAFM) and scanning tunneling microscopy (STM). It was observed that Nb doping does not affect the magnitude of the strain-induced polarization, yet still significantly affects the morphology, the electronic structure, and the domain-wall structure on cleaved SrTiO3(001) surfaces. Beside demonstrating the interplay between the domain distribution and electrostatic screening, these results show how the properties of these heterogeneous surfaces can be tuned.
[1] Sokolović et al., Phys. Rev. Mater. 3, 034407 (2019)
[2] Sokolović et al., Phys. Rev. B 103, L241406 (2021).