A revisit to defect structure of La_0.1Sr_0.9Co_0.8Fe_0.2O_3−δ (LSCF1982) by considering its molecular chemical form as La_0.1Sr_0.9Co_0.8Fe_0.2O_x+δ, with B-site cations having +2 valence as reference charge, and oxygen interstitials (O_i″) and localized holes as majority ionic and electronic defects, have shown agreement between experimentally measured defect-chemical-properties and those calculated using regular solution model. With respect to oxygen nonstoichiometry (δ), the defect structure showed a positive deviation from ideal solution behavior. However, this regular solution model fails to account for variations of electronic thermopower and electronic conductivity in high oxygen partial pressure regions. In this work, we have analyzed the defect structure in terms of the degeneracy of holes and reinterpreted the positive deviation in defect chemical properties in terms of the activity coefficient of delocalized holes (γ_h). It is observed that the positive deviation can be ascribed to hole degeneracy, which is quantified by using Joyce-Dixon approximation of Fermi-Dirac integral. The Fermi energy relative to the valence band edge has negative values, indicating that it overlaps with the upper edge of valence band and thus suggesting a strong possibility of band conduction. Variation of hole mobility with temperature indicated a metal-type conduction behavior, which can be accounted by the band conduction from degenerated holes.

通过考虑其分子化学形式为La _0.1 Sr _0.9 Co _0.8 Fe _0.2 O _{x +δ}，对La _0.1 Sr _0.9 Co _0.8 Fe _0.2 O _{3 - δ}（LSCF1982）的缺陷结构进行再研究，B位阳离子的价数为+2作为参考电荷和氧气间隙（O _i”）和局部孔（大多数离子和电子缺陷）已显示出实验测量的缺陷化学性质与使用常规溶液模型计算的缺陷之间的一致性。关于氧非化学计量学（δ），缺陷结构显示出与理想溶液行为的正偏差。但是，此常规解决方案模型无法解决高氧分压区域中电子热功率和电子传导率的变化。在这项工作中，我们已经分析了缺陷结构中的孔的简并性方面和离域孔的活度系数方面重新解释在缺陷化学性质的正偏差（γ _ħ）。可以看出，正偏差可以归因于孔的简并性，这可以通过使用费米-狄拉克积分的Joyce-Dixon逼近来量化。相对于价带边缘的费米能量具有负值，表明它与价带的上边缘重叠，因此暗示了很强的带导率。空穴迁移率随温度的变化表明金属类型的导电行为，这可以通过退化空穴的带导来解释。