  NbO2 is a potential material for nanometric memristor devices, both in the
amorphous and the crystalline form. We fabricated NbO2 thin films using
RF-magnetron sputtering from a stoichiometric target. The as-deposited films
were amorphous regardless of the sputtering parameters. Post deposition vacuum
annealing of the films was necessary to achieve crystallinity. A high degree of
crystallinity was obtained by optimizing annealing duration and temperature.
The resistivity of the material increases as it undergoes a structural
transition from amorphous to crystalline with the crystalline films being one
order of magnitude more resistive.
