Non-hysteretic metal–insulator transition of VO2 films grown by excimer-laser-assisted metal organic deposition process

Abstract

We examined the correlation between thickness of an epitaxial VO2 phase grown on a TiO2 (001) substrate by the excimer-laser-assisted metal organic deposition (ELAMOD) process and the metal–insulator transition (MIT) property of it. The abrupt and hysteretic MIT was observed for the epitaxial films (thickness: t≥6nm), and the epitaxial film (t≤4nm) showed semiconductor behavior. When an amorphous VOx layer was prepared on the ultrathin epitaxial phase (t≤4nm) by the ELAMOD, a non-hysteretic MIT was successfully observed. The non-hysteretic MIT was found to be owing to roughened interface between the epitaxial phase and the amorphous phase, where there would be a number of structural defects.