SKM 2023 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 47: Oxide Semiconductors II
HL 47.1: Talk
Friday, March 31, 2023, 09:30–09:45, POT 81
Origin of Resistive Switching in SrTiO3 — •Wahib Aggoune1, Christian Carbogno1, Martin Albrecht2, and Matthias Scheffler1 — 1The NOMAD Laboratory at the FHI of the Max-Planck-Gesellschaft and IRIS-Adlershof of the Humboldt-Universität zu Berlin. — 2Leibniz-Institut für Kristallzüchtung, 12489 Berlin.
Memristors may play a key role for the next generation of non-volatile memory devices. They are typically realized using materials that allow to switch between a low- and a high-resistance state. This effect has been recently observed in SrTiO3 thin films, whereby a pronounced dependence of the switching properties on the growth conditions was found [1,2]. To shed light on the underlying atomistic mechanisms, we performed density-functional theory calculations and carefully analyzed the critical effects of different exchange-correlation functionals. We explored the most stable defects (vacancies, interstitial, substitutional) under Ti-rich conditions. The study reveals that the formation of a TiSr antisite defect is energetically favorable and also induces a spontaneous polarization. It can be further stabilized by an additional nearby Sr-vacancy (TiSr+VSr). Furthermore, such a defect complex increases the observed polarization. We discuss these results with respect to the experimentally observed resistive switching by analyzing the electronic properties and the polarization as well as the energy barriers for switching it.
[1] A. Baki, et al., Sci. Rep. 11, 7497 (2021).
[2] K. Klyukin, et al., Phys. Rev. B 95, 035301 (2017).