Metal-oxide-based resistive switching (RS) devices have applications in non-volatile mass storage and understanding their underlying physics has attracted much attention with a number of models to predict switching mechanisms.
It has been predicted that some metal-insulator-metal (MIM) resistive switching devices produce H2 but has remained unreported. However, Qiaonan Yin et al have, in their recent Letter published in JPhysD, experimentally observed cathode bubbles in Pt/TiO2−x/Pt RS cells following implementation of electroforming in a humid environment. Comparatively, these bubbles do not appear in an anhydrous environment.
The researchers from Nanjing University — having used the focused ion beam technique (FIB) to observe the deformation of the cells due to the bubbles — have deduced the bubbles are filled with H2. They ascribe the production of these H2-filled bubbles at the cathode is due to the reduction of adsorbed water.
This figures shows (a) – (c) the separation between the bottom electrode (BE) and the under layers of the Pt/TiO2−x/Pt RS cell due to bubble cracking; and (d) similar separation for the quartz substrate.

Separation between the bottom electrode (BE) and the under layers of the Pt/TiO2−x/Pt RS cell due to bubble cracking from Qiaonan Yin et al 2016 J. Phys. D: Appl. Phys. 49 09LT01
This work is licensed under a Creative Commons Attribution 3.0 Unported License. Thumbnail image (adapted) and image used in post: Qiaonan Yin et al 2016 J. Phys. D: Appl. Phys. 49 09LT01. Copyright IOP Publishing 2016.
Categories: Journal of Physics D: Applied Physics