Tsvetkov Dmitry, Ivanov Ivan, Malyshkin Dmitry, Sereda Vladimir, Zuev Andrey
Institute of Natural Sciences and Mathematics, Ural Federal University, 620000 Ekaterinburg, Russia.
Institute of High Temperature Electrochemistry, Ural Branch of Russian Academy of Sciences, 620000 Ekaterinburg, Russia.
Membranes (Basel). 2019 Sep 13;9(9):120. doi: 10.3390/membranes9090120.
BaZrYO (BZY10), a promising proton conducting material, exhibits p-type conduction under oxidative conditions. Holes in BZY10 are of the small polaron type. However, there is no clear understanding at which places in the lattice they are localized. The main objectives of this work were, therefore, to discuss the nature of electronic defects in BZY10 on the basis of the combined measurements of the thermo-EMF and conductivity. Total electrical conductivity and Seebeck coefficient of BZY10 were simultaneously studied depending on partial pressures of oxygen (), water () and temperature (). The model equation for total conductivity and Seebeck coefficient derived on the basis of the proposed defect chemical approach was successfully fitted to the experimental data. Transference numbers of all the charge carriers in BZY10 were calculated. The heat of transport of oxide ions was found to be about one half the activation energy of their mobility, while that of protons was almost equal to the activation energy of their mobility. The results of the Seebeck coefficient modeling indicate that cation impurities, rather than oxygen sites, should be considered as a place of hole localization.
BaZrYO（BZY10）是一种很有前景的质子传导材料，在氧化条件下表现出p型传导。BZY10中的空穴属于小极化子类型。然而，对于它们在晶格中的定位位置尚无明确认识。因此，这项工作的主要目标是基于热电动势和电导率的联合测量来讨论BZY10中电子缺陷的性质。根据氧分压（）、水（）和温度（），同时研究了BZY10的总电导率和塞贝克系数。基于所提出的缺陷化学方法推导的总电导率和塞贝克系数的模型方程成功拟合了实验数据。计算了BZY10中所有电荷载流子的迁移数。发现氧离子的迁移热约为其迁移活化能的一半，而质子的迁移热几乎等于其迁移活化能。塞贝克系数建模结果表明，阳离子杂质而非氧位点应被视为空穴定位的位置。
