We have observed a persistent x-ray induced insulator-metal transition at low temperature for an epitaxial film of electron-doped VO2, a material as characterized by strong electron-electron and electron-lattice interactions. The volume fraction of the photo-generated metallic patches, ranging from 0 to 100% of the whole film, can be scaled well with the total dose of x-ray irradiation, irrespective of the x-ray intensity. This indicates the monomolecular process of the insulator-metal phase conversion that corresponds to the instantaneous creation of the metallic patch extending over as many as 105 V sites per one x-ray absorbed photon. The typical percolation behavior is observed in the conductivity change with the finely photo-controlled volume ratio of the metallic phase.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2011 Oct 10|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics