J. E. Stroud1, W. C. TRIPP1, J. M. Wimmer2
1Systems Research Laboratories, Incorporated, Dayton, Ohio 45440
2Aerospace Research Laboratories Wright-Patterson Air Force Base, Ohio 45433
Tóm tắt
Electrical conductivity, thermoelectric power, and weight change were measured for polycrystalline Ta2O5 from 900° to 1400°C. The predominant ionic and electronic defects in this temperature range are oxygen vacancies and electrons. The oxygen‐vacancy and electron mobilities are 8.1 × 103exp (−1.8 eV/kT) and ∼0.05 cm2/V‐s, respectively. At O2 partial pressures near 1 atm, the ionic‐defect concentration is essentially fixed by the presence of lower‐valence cation impurities, and the total electrical conductivity is predominantly ionic, whereas at low Po2's the conductivity is electronic and proportional to PPo2−1/6.
