Agarkov Dmitrii, Borik Mikhail, Korableva Galina, Kulebyakin Alexey, Kuritsyna Irina, Larina Nataliya, Lomonova Elena, Milovich Filipp, Myzina Valentina, Ryabochkina Polina, Tabachkova Nataliya, Volkova Tatyana, Zakharov Denis
Osipyan Institute of Solid State Physics RAS, Academician Osipyan Str., 2, 142432 Chernogolovka, Moscow District, Russia.
Moscow Institute of Physics and Technology, Instituskiy per., 9, 141701 Doloprudny, Moscow District, Russia.
Membranes (Basel). 2023 Mar 9;13(3):312. doi: 10.3390/membranes13030312.
The effect of long-term high-temperature annealing on the phase composition, local crystal structure, and oxygen-ion conductivity of SOFC membranes based on zirconium dioxide solid solutions was studied. Crystals with the composition of (ZrO)(ScO)(RO) (where x = 0.08-0.1; R-Yb, Y, Tb, Gd) were obtained by the method of directed melt crystallization in a cold crucible. The crystals were annealed in air at a temperature of 1000 °C for 400 h. The phase analysis of the crystals before and after annealing was studied by X-ray diffractometry and Raman spectroscopy. The study of the ionic conductivity of the crystals was carried out by the method of impedance spectroscopy in the temperature range 400-900 °C. It has been shown that when various rare earth cations (Yb, Y, Tb, and Gd) are used, the maximum conductivity is observed for the compositions (ZrO)(ScO)(YbO), (ZrO)(ScO)(YO), (ZrO)(ScO)(TbO), and (ZrO)(ScO)(GdO). At the same time, these crystals have a highly symmetrical pseudocubic structure, which is retained even after crystal annealing. At comparable concentrations of ScO, the conductivity of crystals decreases with an increase in the ionic radius of the rare earth cation. The high-temperature degradation of the conductivity is also discussed depending on the type of rare earth oxide and the concentration of scandium oxide.
研究了长期高温退火对基于二氧化锆固溶体的固体氧化物燃料电池（SOFC）膜的相组成、局部晶体结构和氧离子传导率的影响。通过冷坩埚中的定向熔体结晶法获得了组成为(ZrO)(ScO)(RO)（其中x = 0.08 - 0.1；R = Yb、Y、Tb、Gd）的晶体。将晶体在空气中于1000℃退火400小时。通过X射线衍射和拉曼光谱研究了退火前后晶体的相分析。通过阻抗谱法在400 - 900℃温度范围内对晶体的离子传导率进行了研究。结果表明，当使用各种稀土阳离子（Yb、Y、Tb和Gd）时，对于(ZrO)(ScO)(YbO)、(ZrO)(ScO)(YO)、(ZrO)(ScO)(TbO)和(ZrO)(ScO)(GdO)组成观察到最大传导率。同时，这些晶体具有高度对称的假立方结构，即使在晶体退火后也能保留。在ScO浓度相当的情况下，晶体的传导率随着稀土阳离子离子半径的增加而降低。还根据稀土氧化物的类型和氧化钪的浓度讨论了传导率的高温降解情况。
