The oxygen ion migration-induced resistive switching is a complex process with multiple mechanisms. This study investigated resistive switching properties and mechanism for strongly correlated materials lanthanum titanium oxide La2Ti2O7-x (LTO) using spectromicroscopy and density functional theory simulation. Bipolar resistive switching without an electroforming process was first reported in LTO film. The mechanism can be explained by oxygen ion migration induced band-filling controlled Mott transition in LTO. Oxygen ion migration-induced reduction and oxidation of LTO can increase and decrease Ti 3d orbital filling state, which in turn increases and reduces Mott-Hubbard gap and LTO resistance, respectively. In addition, the RRAM device, TiN/LTO/Pt, shows stable endurance, retention, and small variability at room temperature and 85 ℃, with a stable on/off-state current density, which is independent of the electrode size. This work not only demonstrates that LTO and other strongly correlated materials are potential candidates to prepare resistive random access memory based on oxygen ion migration induced Mott-transition mechanism but also indicates that intrinsic resistance change in switching layers between top and bottom electrodes also contribute to overall resistive switching.
|Journal||Applied Materials Today|
|Publication status||Published - 2022 Mar|
Bibliographical noteFunding Information:
This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (Grant 2019R1A2C2087604). This work was also supported by Creative Materials Discovery Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT (Grant 2018M3D1A1058536 ). Yue Wang would like to thank the China Scholarship Council (CSC) for financial support.
© 2022 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Materials Science(all)