In-Situ Observation of the Electrical Conductivity upon Release and Uptake of Oxygen in Indium Tin Oxide Sinter

The electrical conductivity, the oxygen release and uptake of sintered indium tin oxide (ITO) upon heating and cooling under the condition that P(O2)/P *=4.9×10-4 (P *=atmospheric pressure), when P(O2) was approximately 50 Pa, were simultaneously observed. Two kinds of oxygen release and uptake were detected in the different temperature ranges of 973<T<1130 K and 1130<T<1273 K. Electrical conductivity was increased as a result of the increase in carrier concentration due to oxygen release at the higher temperature, although the conductivity was not altered by the oxygen release at the lower temperature. Decrease in the mobility of conduction electrons could be explained in terms of the increase in the concentration of the scattering centers induced by release and uptake of oxygen atoms.