Direct evidence for the coexistence of nanoscale high-conduction and low-conduction phases in VO2 films
A systematic investigation of the nanoscale conduction behavior of vanadium dioxide (VO2) films deposited on aluminum oxide (Al2O3) substrates, using conductive atomic force microscopy, is presented. Aside from the macroscale resistance-temperature characteristics, which show a steep insulator-metal...
Gespeichert in:
Veröffentlicht in: | Applied physics letters 2018-10, Vol.113 (17) |
---|---|
Hauptverfasser: | , , , , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | A systematic investigation of the nanoscale conduction behavior of vanadium dioxide (VO2) films deposited on aluminum oxide (Al2O3) substrates, using conductive atomic force microscopy, is presented. Aside from the macroscale resistance-temperature characteristics, which show a steep insulator-metal transition at the transition point Tm ∼ 68 °C, our experiments demonstrate a coexistence of nanoscale high-conduction and low-conduction phases over a broad temperature window (50 K range) across the Tm. In addition, the area (volume) fraction of the high-conduction phase increases with increasing temperature across the transition point. The current-voltage data obtained on a nanoscale indicate that the high-conduction phase is not a good metal. When the temperature increased across the Tm, the probed charge transport behavior of the high-conduction phase is found to change from a mechanism dominated by space-charge limited current to a mechanism dominated by Schottky emission. |
---|---|
ISSN: | 0003-6951 1077-3118 |
DOI: | 10.1063/1.5032270 |