Optimization of ionic transport through mixed conducting oxide ceramics

摘要: Abstract Ceramics exhibiting both electronic and ionic conductivities can be obtained by doping highly oxygen conducting matrices with multivalent cations. These materials allow transport to occur under open circuit conditions driven an chemical potential gradient only. In the present work, equations are developed which express this flux as a function of environmental material variables. For small PO2 gradients, is maximized when tO2- = te- 0.5. To treat case significant more general analysis has been carried out using model system, ZrO2-Y2O3-MO2, where M Ce or Ti. The extrinsic electron conductivity due dopant exhibits maximum plotted either temperature PO2. As result, inflexion point observed at critical pressure, PcO2 in curve describing through Below PcO2, rapidly approaches saturation value, JmaxO2-. Both JmaxO2- shown functions composition. variation also discussed.