Physical properties of VO$_{2}$ and V$_{2}$O$_{3}$ nanowires.

Both VO$_{2}$ and V$_{2}$O$_{3}$ show dramatic metal-insulator transitions, whose manifestations on the nanoscale are not known. We investigate techniques to differentiate and pattern the metallic and insulating domains in small VO$_{2}$ crystals and nanowires grown by vapor phase deposition. For instance, it has been reported that insulating VO$_{2}$ can be metallized by electron beam exposure and by hydrogenation. We attempt to distinguish the domains by scanning probe techniques, including topography and electric force microscopy, and observe a pinning effect of the domains by oscillating strain variations when the nanowire is attached to a substrate. When the strain is released by etching, the pinning is removed. The VO$_{2}$ crystals can be converted to V$_{2}$O$_{3}$ crystals by reducing in hydrogen and annealing. By patterning the V$_{2}$O$_{3}$ on the nanoscale we aim to realize strongly correlated quantum dots.