Ceria electrolytes oxygen partial pressure dependency

The most common electrolyte material is YSZ. Another central one is yttria-(YDC) or gadolinia-doped ceria (GDC). Despite its higher ionic conductivity than 8 YSZ, its drawback are non-negligible electronic conduction at low oxygen partial pressure and isothermal expansion. It can also serve as a compatibility layer, to prevent undesirable reactions between the YSZ electrolyte and an LSCF cathode. The CTEs of both materials exhibit temperature dependence. SRU typically have to withstand spatial temperature differences of 100 K, e.g. 973-1073 K. The corresponding variation of the CTE between RT and 1073 K in one data set is of approximately 9.8—11.0 x 10 for 8YSZ and 12.1 —12.9 x 10 K for GDC, which can lead to imprecision in the calculation of the stress field. 

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