Issue 29, 2016

Verification of redox-processes as switching and retention failure mechanisms in Nb:SrTiO3/metal devices

Abstract

Nanoscale redox reactions in transition metal oxides are believed to be the physical foundation of memristive devices, which present a highly scalable, low-power alternative for future non-volatile memory devices. The interface between noble metal top electrodes and Nb-doped SrTiO3 single crystals may serve as a prominent but not yet well-understood example of such memristive devices. In this report, we will present experimental evidence that nanoscale redox reactions and the associated valence change mechanism are indeed responsible for the resistance change in noble metal/Nb-doped SrTiO3 junctions with dimensions ranging from the micrometer scale down to the nanometer regime. Direct verification of the valence change mechanism is given by spectromicroscopic characterization of switching filaments. Furthermore, it is found that the resistance change over time is driven by the reoxidation of a previously oxygen-deficient region. The retention times of the low resistance states, accordingly, can be dramatically improved under vacuum conditions as well as through the insertion of a thin Al2O3 layer which prevents this reoxidation. These insights finally confirm the resistive switching mechanism at these interfaces and are therefore of significant importance for the study and application of memristive devices based on Nb-doped SrTiO3 as well as systems with similar switching mechanisms.

Graphical abstract: Verification of redox-processes as switching and retention failure mechanisms in Nb:SrTiO3/metal devices

Supplementary files

Article information

Article type
Paper
Submitted
29 jan 2016
Accepted
28 mar 2016
First published
30 mar 2016
This article is Open Access
Creative Commons BY license

Nanoscale, 2016,8, 13967-13975

Author version available

Verification of redox-processes as switching and retention failure mechanisms in Nb:SrTiO3/metal devices

C. Baeumer, N. Raab, T. Menke, C. Schmitz, R. Rosezin, P. Müller, M. Andrä, V. Feyer, R. Bruchhaus, F. Gunkel, C. M. Schneider, R. Waser and R. Dittmann, Nanoscale, 2016, 8, 13967 DOI: 10.1039/C6NR00824K

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements