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VOx Phase Mixture of Reduced Single Crystalline V2O5:VO2 Resistive Switching
The strongly correlated electron material, vanadium dioxide (VO2), has seen considerable
attention and research application in metal-oxide electronics due to its metal-to-insulator transition
close to room temperature. Vacuum annealing a V2O5(010) single crystal results in Wadsley phases
(VnO2n+1, n > 1) and VO2. The resistance changes by a factor of 20 at 342 K, corresponding to the
metal-to-insulator phase transition of VO2. Macroscopic voltage-current measurements with a probe
separation on the millimetre scale result in Joule heating-induced resistive switching at extremely low
voltages of under a volt. This can reduce the hysteresis and facilitate low temperature operation of
VO2 devices, of potential benefit for switching speed and device stability. This is correlated to the low
resistance of the system at temperatures below the transition. High-resolution transmission electron
microscopy measurements reveal a complex structural relationship between V2O5, VO2 and V6O13
crystallites. Percolation paths incorporating both VO2 and metallic V6O13 are revealed, which can
reduce the resistance below the transition and result in exceptionally low voltage resistive switching.