A slight Nb₂O₅ co-doping in 11Sc₂O₃-89ZrO₂ was earlier reported to stabilize the high-symmetry cubic phase completely and enhances the conductivity significantly. The present work looked at the temporal stability of conductivity in 1Nb₂O₅-10Sc₂O₃-89ZrO₂ (1Nb10ScSZ) for the electrolyte application in solid oxide fuel cells. In-situ conductivity measurement was done using impedance spectroscopy at 650 °C in the air for 2000 h. A substantial conductivity loss (29%) was observed in the first 1000 h. Following which, conductivity remained relatively stable for the next 1000 h. Impedance analysis showed that the main contribution to the conductivity degradation was from grain conductivity. Phase analysis performed using XRD, TEM and Raman spectroscopy revealed that both the unaged and aged 1Nb10ScSZ samples consisted of metastable t″-phase. However, the extent of tetragonality was found to increase after ageing. The formation of low-symmetry phase was suggested to be the reason for the grain conductivity loss in 1Nb10ScSZ.

早先有报道称，在11Sc ₂ O ₃ -89ZrO _2中掺入少量Nb ₂ O ₅可以完全稳定高对称立方晶相，并显着提高电导率。本工作着眼于固体氧化物燃料电池中电解质应用的1Nb ₂ O ₅ -10Sc ₂ O ₃ -89ZrO ₂（1Nb10ScSZ）中的电导率的时间稳定性。原位电导率的测量是使用阻抗光谱仪在650°C的空气中进行2000 h。在最初的1000小时内，观察到了较大的电导率损失（29％）。之后，电导率在接下来的1000小时内保持相对稳定。阻抗分析表明，导致电导率降低的主要因素是晶粒电导率。使用XRD，TEM和拉曼光谱进行的相分析表明，未老化和老化的1Nb10ScSZ样品均由亚稳态t''相组成。然而，发现老化后四边形的程度增加。认为低对称相的形成是造成1Nb10ScSZ晶粒电导率损失的原因。