Point Defect Structure of Cr203
Abstract
Chromium oxide, Cr2O3 is of considerable technological importance because it provides a protective scale on important materials, such as stainless steels and superalloys; therefore, it is of interest to know its transport properties and how these properties may be altered. In order to obtain a better understanding of the defect structure of Cr2O3, the electrical conductivity and Seebeck coefficient of sintered high purity Cr2O3, Titanium Dioxide, TiO2-doped Cr2O3 and Magnesium Oxide MgO-doped Cr2O3 have been measured as functions of temperature, oxygen partial pressure and different levels of dopant content. Results from these measurements show that the defect structure of Cr2O3 is relatively complicated. At high temperatures, depending upon the oxygen partial pressure different defects may present. In general, at high Phosphorus Oxide, PO2, Cr2O3 is a P-type semiconductor with electron holes and chromium vacancies as the predominant defects; at intermediate PO2, Cr2O3 behaves as an intrinsic semiconductor with electron and electron holes as the major defects; at low PO2, near the Cr/Cr2O3 equilibrium oxygen pressure, Cr2O3 changes to an N-type semiconductor with electrons and chromium interstitials as the dominant defects. Keywords: Semiconductors, Electrical conductivity, Point defect structure, High temperature oxidation, Thermoelectric power.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1987
- Accession Number
- ADA187620
Entities
People
- G. Simkovich
- M. Y. Su
Organizations
- Pennsylvania State University