Metal-insulator transition in VO2 macro single domain crystals due to phase boundary motion

Metal insulator transition (MIT) characteristics of macro-size VO$_{2}$ single domain crystals, exhibiting a high resistance ratio of $\sim $ 10$^{5}$ within as small as-10$^{-3} \quad ^{\circ}$C in the vicinity of MIT temperature, were investigated by temperature-dependent electrical transport, optical microscopy, and synchrotron-based polychromatic x-ray micro-diffraction measurements. Our results clearly show that MIT initiated via inhomogeneous nucleation, proceeds with the propagation of sharp phase boundary between the metallic (R) and insulating (M1) phases, along the rutile c axis. In this talk, we will present evidences of MIT of single domain VO$_{2}$ crystals with sharp phase boundary motion and discuss the implications of our findings on to the origin of MIT and related phenomena.