Kritischer Temperaturbereich. Verschieden orientierte Bereiche der doppelbrechenden Tieftemperaturphase. Halbleitende und metallische Phase bei VO[2]-Einkristallnadeln. Domänenwanderung. Peltier-Effekt. Mit Zeitraffung.

At a critical temperature of 65,5°C, vanadium oxide crystals exhibit a structural transformation which is associated with a semiconductor-to-metal transition. The double-refractive, low-temperature phase is split up into differently oriented domains which can be rendered visible under a polarization microscope. Filmed through such a microscope, the film shows the transitions between semiconducting and metallic phases of vanadium oxide monocrystal needles. The transformations are caused by the external application of heat or by current flow with defined angles resulting between the domain walls and the crystal axes. In the case of current passing through the crystals there are, in addition, domain migrations which are due to the Peltier Effect and depend upon the direction of the current flow.