Optical image of a VO2 nanoplatelet with lighter insulating monoclinic (M2 phase) and darker metallic tetragonal (R phase) domains. The domains are self-organized during current passage into triangular shapes by Joule heating. The Laue diffraction patterns at the bottom of the figure taken with a 0.5 µm-diameter polychromatic microbeam demonstrated that the two types of domains coexist within the VO2 nanoplatelet. Adapted from Tselev et al. (2011) with permission.