On the Defect Structure fo Rutile

II. Dependence of the Electrical Conductivity of High Purity Polycrystalline Rutile on Equilibrium Oxygen Pressure and Temperature

抄録

1) The electrical conductivity of high purity polycrystalline rutile prepared from T.B.T. was determined as a function of the oxygen partial pressure (10^-2-10³ mmHg) at 800° and 900°C. The electrical conductivity has been found proportional to Po₂^-1/6.
2) The frequency dispersion of the conductivity was not observed at 800° and 900°C, and the dc conductivity data corresponded to those of ac.
3) The relation logσ vsl/T was well represented by a straight line having a slope 1.48eV in pure oxygen gas and in the temperature range 600°-1000°C.
4) In the thermoelectric power measurements, the cooler end of the specimen was always negative with respect to the hotter end indicating negative charge carriers, electrons, but the quantitative values could not be obtained with a reproducibility.
5) It may be concluded that the defect of rutile with a "nearly intrinsic" character involves oxygen vacancies at 800° and 900°C in the oxygen partial pressure 10^-2-10³ mmHg, and it appears to imply that p-type conduction did not belong to the intrinsic behavior of rutile below atmospheric pressure.