Resistive random access memory (ReRAM) properties in which the resistance of the insulating material drastically changes by voltage application have recently attracted much attention. In this work, molybdenum oxide prepared by thermal oxidation of Mo films was studied to investigate its potential as a material exhibiting ReRAM switching. The samples oxidized between 400 and 600 degrees C were composed of MoO3 and were switchable. Current-to-voltage curves, which were measured in air at room temperature by using a Pt-Ir probe as the top electrode, indicated the yielding of both the monopolar and bipolar switching properties. The resistance on-off ratio was between 10 and 10(2). (C) 2011 Elsevier B.V. All rights reserved.