  The single crystal VO2, exihibiting a first-order metal-insulator transition
(MIT) at 67.2 degrees C and an insulator-insulator transition (IIT) at ~49.7
degrees C, is grown. From synchrotron-based x-ray microdiffraction analysis,
the IIT shows structural phase transition (SPT) of monoclinic M2 to M1 phases
while the MIT displays M1 to rutile R phases. The IIT exhibits percolative SPT
while the MIT shows abrupt transition width of < 0.02 degrees C, supporting
Mott's prediction. The MIT occurs non-percolatively with a sharp boundary
between R and M1 phases. The MIT onset temperature shows significant variation.
