Permeation in Dense Oxide Membranes

As described in Section 8.2.6, along with YSZ, mixed oxygen-ion, and electron-conducting oxides with a perovskite-type structure, the so-called Aurivillius phase and pyrochlore materials are fundamentally used for the production of a variety of high-temperature electrochemical devices [50-58], 

When oxygen is transported through a membrane in a steady state, there is no net charge current and the flux of oxygen anions, O2-, can be written using the ambipolar diffusion expression, as follows [49] 

The Physical Chemistry of Materials Energy and Environmental Applications 

if we know both constants, it is possible to integrate Equation 10.13 to get an explicit expression for the oxygen flux. 

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