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 t hat P(O-2)/P = 4.9 x 10(-4) (P*=atmospheric pressure), when P(Oa) was approximately 50 Pa, were simultaneously observed. Two kinds of oxyge n release and uptake were detected in the different temperature ranges of 973 < T < 1130 K and 1130 < T < 1273 K. Electrical conductivity wa s increased as a result of the increase in carrier concentration due t o oxygen release at the higher temperature, although the conductivity was not altered by the oxygen release at the lower temperature. Decrea se in the mobility of conduction electrons could be explained in terms of the increase in the concentration of the scattering centers induce d by release and uptake of oxygen atoms.