Contact effects in devices incorporating strongly correlated electronic materials are comparatively unexplored. We have investigated the electrically driven phase transition in magnetite (100) thin films by four-terminal methods. In the lateral configuration, the channel length is less than 2μm, and voltage-probe wires ∼100nm in width are directly patterned within the channel. Multilead measurements quantitatively separate the contributions of each electrode interface and the magnetite channel. We demonstrate that on the onset of the transition contact resistances at both source and drain electrodes and the resistance of magnetite channel decrease abruptly. Temperature-dependent electrical measurements below the Verwey temperature indicate thermally activated transport over the charge gap. The behavior of the magnetite system at a transition point is consistent with a theoretically predicted transition mechanism of charge gap closure by electric field.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jan 25 2010|
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials