SEMICONDUCTION AND MIXED IONIC-ELECTRONIC CONDUCTION IN NONSTOICHIOMETRIC OXIDES - IMPACT AND CONTROL

Factors controlling electronic conduction in oxides are first discusse d. Criteria for achieving predominant ionic conduction are then develo ped. The role of nonstoichiometry in influencing mixed ionic-electroni c conductivity, MIEC, is then evaluated, followed by an examination of the impact of MIEC on electrochemical cell performance, oxygen permea tion, and redox kinetics. Means for manipulation and control of MIEC a re illustrated with examples drawn from the author's research on pyroc hlore oxides.