Voltage-induced insulator-to-metal transition of hydrogen-treated NbO2thin films

We report on the voltage-induced insulator-to-metal transition (IMT) of the NbO 2 thin films that are deposited under forming gas in the growth chamber. It is shown that the hydrogen in the forming gas gives rise to the abrupt voltage-induced IMT characteristics in NbO 2 thin films that are sandwiched between top and bottom Pt electrodes. By a catalytic reaction at the triple boundary between NbO 2 and Pt, hydrogen appears to be easily incorporated into the NbO 2 lattice and doping significantly lowers the IMT temperature of NbO 2 thin films, along with the reduction of NbO 2 films.