Large anisotropy in conductivity of Ti2O3 films

Abstract

We investigated electronic properties of Ti2O3 films with film thickness of ∼150 nm. The temperature dependence of resistivity indicated characteristic phase transitions. The insulator-to-metal transition (IMT) temperature (TIMT) deviated from bulk TIMT of ∼450 K. The higher and lower TIMTs of 450–600 K and 200–300 K were found in a- and c-axes oriented films, respectively. In addition, the large anisotropy in conductivity parallel and perpendicular to the c-axis direction was observed in the insulating phase, which was attributed to large difference in Hall mobility. The higher TIMT far above room temperature and the large difference in resistivity across the IMT were promising characteristics for application of Ti2O3 films in Mottronics.