Module 2: Defect Chemistry and Defect Equilibria
  Defect Structures in Non-Stoichiometric Oxides
 


       2.5 Defect Structures in Non - Stoichiometric Oxides

  • Mainly of two types

    1. Oxygen deficient (or excess metal)

    2. Metal deficient (or excess oxygen)

  • Nonstoichiometry necessitates presence of point defects and extent of non-stoichiometry determines the concentration of Defects.

  • In such oxides, electrical neutrality is preserved via the formation of point defects and electronic changes.

  • Intrinsic ionization is always a possibility.