Observation of a uniform temperature dependence in the electrical resistance across the structural phase transition in thin film vanadium oxide (VO2)

An electrical study of thin VO2 films in the vicinity of the structural phase transition at 68 degrees C shows (a) that the electrical resistance R follows log(R)proportional to-T over the T range, 20 < T < 80 degrees C covering both sides of the structural transition, and (b) a history dependent hysteresis loop in R upon thermal cycling. These features are attributed here to transport through a granular network.