Point Defect Structure of Chromium (III) Oxide
Based upon studies of the electrical conductivity and Seebeck coefficient of TiO2- and MgO-doped Cr2O3, the point defect structure of Cr2O3 was determined. It is found that the defect and transport properties in Cr2O3 are complicated. At high temperatures, different defects may be present depending upon the oxygen partial pressure. In general, at high PO2, Cr2O3 is a p-type semiconductor with electron holes and chromium vacancies as the dominant defects; at intermediate PO2, it behaves as an intrinsic semiconductor with electrons and electron holes dominant; and at low PO2, near the Cr/Cr2O3 equilibrium oxygen pressure, it changes to an n-type semiconductor with electrons and chromium interstitials dominant. The equilibrium constants associated with the formation of different defects are also obtained.
KeywordsDefect Structure Oxygen Partial Pressure Seebeck Coefficient Dopant Content Electron Hole
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