Nonohmic Behavior in Near-Stoichiometric Rutile (TiO2)

Abstract

Experimental observations of the isothermal current-voltage relationships in rutile (TiO2) over the temperature range 632°–908°C have shown that currents in excess of ohmic currents can be drawn through small, single crystals of near-stoichiometric composition. These currents have been identified as space-charge-limited currents analogous to those observed in the case of a vacuum diode. An increase in the ambient specimen temperature had the effect of displacing the potential for transition from ohmic to non-ohmic behavior to greater values so that, at 908°C, near-stoichiometric rutile exhibited only ohmic currents even at the largest fields employed.