Electric field-induced conductivity switching in vanadium sesquioxide nanostructures
Abstract/Contents
- Abstract
- Strong interactions, or correlations, between the d or f electrons in transition metal oxides can lead to various types of metal-insulator transitions which may be triggered by external parameters such as temperature, pressure, doping and magnetic field. Recent theoretical and experimental reports have suggested that this transition can also be triggered by a threshold electric field. Fully realized, this effect could lead to an entirely new class of electronic switches based on materials with strongly correlated electron systems. However, significant questions remain about the detailed nature of the experimental results, especially the degree to which Joule heating plays a role. In this work, we present an investigation of time-resolved, voltage-induced conductivity switching in the canonical metal-insulator transition system V2O3. The main findings can be categorized into three parts: film growth, electrical measurement, and electro-thermal modeling. First we discuss the growth, optimization and characterization of high-quality epitaxial V2O3 films, including the effect of oxygen pressure, substrate temperature and substrate material on the film properties. Next we show experimental results on electric field-induced phase transitions in V2O3 nanostructures fabricated by electron beam lithography. We observe that a threshold electric field of approximately 10^7 V/m applied across two-terminal nanostructures causes a metallization of V2O3's low-temperature Mott insulating state, preceded by a nanosecond-scale delay time. Lastly, we explore the feasibility of Joule heating as an explanation for the switching process. After fully accounting for temperature-related feedback and subthreshold nonlinear current-voltage characteristics, we find remarkably good agreement between the predicted and observed threshold voltages and switching delay times as a function of temperature, suggesting the switching mechanism is thermal in origin. We believe these findings have important implications for recent reports of voltage-induced switching in the related materials VO2 and Fe3O4 and will also help to guide future research on this phenomenon.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Brockman, Justin Samuel |
|---|---|
| Associated with | Stanford University, Department of Applied Physics |
| Primary advisor | Harris, J. S. (James Stewart), 1942- |
| Primary advisor | Parkin, Stuart S. P |
| Thesis advisor | Harris, J. S. (James Stewart), 1942- |
| Thesis advisor | Parkin, Stuart S. P |
| Thesis advisor | Goldhaber-Gordon, David, 1972- |
| Advisor | Goldhaber-Gordon, David, 1972- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Justin Brockman. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Justin Samuel Brockman
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...